Does it have to only be on the internet?
And what do you mean by "strange"? Like strange as in "wow, I never expected anyone to use that to get high" or strange as in effects? Or strange as in chemical structure?
DXM is probably the strangest drug I've ever personally done. It's got dissociative/psychedelic properties & it's chemical structure is similar to that of an opioid (it's the d-isomer of levorphanol actually), though it doesn't really possess any opioid activity. In high enough doses it can cause out of body experiences, near-death-like experiences and I truly believe it even has some sort of paranormal or supernatural component to it (but that's a long story).
Some of my old DXM trips completely rivaled any mushroom or acid trips I've taken. But it's got a lot of physical side effects & I don't think I'd be able to handle it anymore at my age. It's not as visual as LSD or anything though. The trip is mostly an "internal" trip, if that makes sense. Although there are some hallucinations.
When I was 27, I went on a 900mg extended release DXM trip & smoked some weed at the peak. I suddenly felt like I was outside of my body & that I was watching my life play out as a movie that was about to end. I thought for sure I was going to die (thought I had accidentally taken too much or that an organ was shutting down). I basically laid on my couch next to my mom thinking I was done for & dying. But eventually I took a klonopin & started to come back to reality. The next day I was very much grateful that I was still alive.
What's strange to me is that something this powerful is available all over the store shelves, but I can't legally walk into a store & buy some opiates? Pfft.