Yes, for me Salvia Divinorum is one of the most mystical experiences a human can have. I do think it depends how you approach it, and despite its overwhelming force I think it is still affected by setting somewhat; I have had different Salvia experiences depending on where I've been, who I've been with, and how I approached it. It is so powerful that it can easily blast you past those aspects of preparation especially at higher doses or with good extracts, but I still think it's wise to prepare yourself properly. Personal recommendation: set up in a nice warm, comfortable environment with dim illumination, and preferably some gentle comforting music to guide the trip. Make sure you have somewhere safe to put the salvia pipe down after inhaling because it can start to overtake you before you've even exhaled.
It is utterly different from conventional serotonergic psychedelics, as you will know having tried it yourself. 4-HO-MET will not prepare your friend for a Salvia experience in itself, although it might prepare him in the sense of being used to a profound shift in consciousness and perception. Side note: 40-60 mg of 4-HO-MET is a megadose, and very overwhelming for most people. I'm sceptical of it, unless his product was cut or he was also on a medication which dampens the effects of psychedelics, or had significant tolerance.
In terms of insights, I suppose the greatest insight I took from my earliest Salvia trips was that the fabric of reality itself is totally different to what we think usually it is, and in a very real, obvious way, not just "I'm trippin balllss maaan!!" sensory distortions. A visceral and palpable - i.e., not merely intellectual or philosophical - understanding, feeling and awareness of very tangible new depths to the fabric of existence and the spacetime manifold itself. And a slippage toward forgetting that the old perception of reality even existed. For example, on my very first trip, which was a strong one, I felt the notorious "salvia gravity" and physically felt myself being pushed sideways by an unseen force. My perception of time stretched out almost to an infinity, and I observed the restlessly changing eigenstates of vibrational modes constituting the unfoldment of events on a sheet of causality that spread out conformally in all directions out to an imperceptibly distant horizon. This sheet expanded to encompass a 3D manifold of time, meaning the standard Cartesian co-ordinate system mapped to directions in time as well as they did in space.
I was only able to track my progress on this sheet due to the steady beat of the gentle music which was playing on the speakers; during the peak I still retained a distant memory of music with a tempo acting as a clock, so I retained the perception of temporal progress. However, as the sheet widened in front of me and around me, I apparently underwent a rapid four-acceleration orthogonal to any normal spatial acceleration in real life; I started experiencing a relativistic Lorentz transformation where I witnessed spatial length contraction and time dilation and widening, to the point that normal "forward" progress in time slowed to a grinding crawl and my progress sideways began to accelerate. Given that gravitational attraction toward a mass is modelled in general relativity as constant motion along an axis of time in curved space, it later occurred to me that "salvia gravity" could be caused by veering off into sideways time, but this was just a playful mental indulgence rather than a serious realization.
The real insight came in that I discovered I could direct myself along whichever path I wanted on this sheet, even though I was far from lucid enough to make any rational decisions. I wasn't bound by a deterministic machine, pushed forward on a single arrow of time by the relentless march of a deterministic clockwork universe. The spacetime path I chose was mine to choose. It destroyed the notion of a block universe of rigid determinism and helplessness, and made me see everything as collective choice and malleable causality. There were simultaneous possibilities next to me on the left and the right, which all looked similar, because the vibrational modes of causality radiated in all 4π steradians but were different on different timelines. Additionally, I had very long horizon of foresight to be able to predict future events based on my estimated current temporal trajectory, and visually being able to see all the interacting timelines to the left and the right. That prediction manifested itself as a visual structure of the eigenstates of the sheet's modes perturbed by the combined wilful choices of other beings and the random classical/probabilistic quantum interactions.
What's more was that if I turned, for example, 90 degrees to the left in time and pursued a different timeline from the 'autopilot' forward one, the structure of shifting eigenstates remained contiguous and made sense, and I could continue on that way and everything would unfold naturally, although my reality would be a different one from that if I had chosen to remain on the previous course. It was basically like a vibrational landscape which looked perfectly right in any direction, and so a conscious being moving orthogonally (sideways) in time relative to us would experience a perfectly normal unfolding of events, even though they would barely zip in and out of our personal light-cones in the space of plank time.
There was a great deal of forward momentum, so it took energy input to turn, in the same way it takes an immense amount of energy to accelerate a particle to near the speed of light, even though from the perspective of the particle it is able to travel across the other side of the universe within a short period of its proper time.
Anyway, it was initially extremely unnerving and felt like I'd been shot out of a space cannon into the outer solar system, a bit like the feeling of loss of control I felt when I first rode "space mountain" at Disneyland as a youngster, but way more intense and confusing. I felt like I had left my former life behind and didn't know how or when I would be able to return, because the time dilation was so extreme; for a few moments in the trip it felt like I had been pulled thousands or millions of years into the "future", even though the word "future" loses all meaning in that space.
As I regained connection with my normal life, which seemed like a very tentative prospect at the peak, I became acutely aware of a great conscious connection to plants. When people talk of the "Salvia spirit" or the "Salvia Goddess" it isn't just hyperbole. Salvia really does feel like a feminine presence breathing itself into you, and safely ushering you, momentarily, up to a summit where you can so fleetingly comprehend the outrageously incomprehensible planes of existence; yet all the while Salvia's spirit seems so earthly, tethering you to something familiar. The abrupt and forceful realization of an astral plane on Earth when you take Salvia, without you having to leave the planet, brings a perception of the world as a garden of Eden or a kind of organic living temple existing in higher consciousness, and even during the peak you are faintly aware of the ground. After my initiating experience, I felt like I'd been wrapped up in Salvia's arms and gently, and very lovingly, shown this incredible vantage point of the universe. And as my first psychedelic trip this completely changed my life for the better.
By the way, I'm not all masquerading that anything I said about physics and relativity is scientifically correct in my description of it; I'm obviously not a physicist and don't pretend to have some grand theory of everything. I don't understand time or space at all, regardless of the hundreds of psychedelic trips. But I also know what I experienced, on multiple occasions, and you can't take those experiences away from me. Scientific theories are just useful models. But experiences are experiences, and they are personal. Make of them what you will.
On smoking Salvia: Much is made of the whole "disrespect" made to the plant by smoking it, and that it should be imbibed orally in quid form to respect the elders etc. I disagree. I feel that smoking Salvia is a totally legitimate and correct way to experience her because you're literally breathing her in. The word "spirit" literally originates from the Latin word "spiritus" which means "breath", "air", or "wind", similarly to the Greek "pneuma". Historically it's defined as the animating force or vital principle in living beings. Nothing feels as real as smoking Salvia, it just feels right.
