I'm going to tell you right now that that forum you found is filled with a lot of guesswork that really doesn't pan out with the scientific evidence. I would take everything said there with a grain of salt, at most.
However, myristicin is definitely psychedelic, and despite tons of claims to the contrary such as mentioned here, I don't believe that there is actually any scientific evidence whatsoever that it is a deliriant. To the contrary, in recent years there have been multiple papers supporting its activity as a 5-HT2A agonist. Parsley, though, is a very poor way to get myristicin. The significantly better option is nutmeg, but not whole nuts.... Those seem like they may contain an anticholinergic, but whatever it is it isn't myristicin. If you want to try this, by far your best option is to look into therapeutic grade nutmeg essential oil. Some places remove the allylbenzenes, but others don't. If you can find one that has a high myristicin content, you can trip on it by ingesting the oil without any deliriant effects.
BUT PLEASE NOTE: This method of using myristicin is still relatively new and entirely unresearched. Though I have not heard of anyone having problems with it yet, it doesn't mean that no one ever will. Please be very cautious and do a lot of research first if you try this.
