I'd love to participate in some of those ceremonies.
Regarding the earlier posts, DXM is a fucking weird drug man. I honestly think it might have some chemical properties that could be important to understanding aspects of the brain as related to its perception of time. I haven't done DXM since my senior year of high school (actually the summer before it to be specific, over which we did it maybe three or four times?). At first we were downing bottles of liquid robitussin, which was horrible and has forever made me want to vomit at even the slightest scent of robitussin. The last time we did it though, we discovered the gel capsules. This allowed us to take a pretty big dose (can't remember exactly, but we're talking handfuls). I know that sounds horribly dangerous, but my friend and I (who's still basically my best friend) we're actually really damn cautious about these kind of "experiments", measuring out dosages as exactly as we could, accounting for active/inactive ingredients, etc. We researched shit pretty intensely before ingesting (I'm also eternally grateful to erowid.com).
Anyway that last DXM trip was probably the craziest drug trip of my life, period. I've done shrooms, salvia, and LSD (though I've never really had a "good" batch of the latter), and nothing compared to DXM. The reason I brought up time is because, even on salvia, I've never experienced the strange perception of time that I did on DXM. I mean my salvia trips lasted ten to twenty minutes and felt like hours or more, but DXM was very unique. There was some dilation of experience (I was watching Animal Planet and a commercial break seemed to last forever), but more than that...and strangely, given that time was stretched within the second-to-second moment...I felt as though I suddenly comprehended how hilariously short the human idea of time is. Like, I was remembering back to my childhood, and the distance from the "now" back to then felt like nothing, less than nothing. Then I started to think about history (at this point I was in the shower, don't ask) and I genuinely felt one of the strongest...I don't know, "revelations", of my life. It was like imagining the history of humanity extending back through the time, and it seemed to go further and further, and yet I was simultaneously realizing how incredibly short that timespan was.
It was also during this same experience that I felt as though I first truly comprehended "life" (and thus humanity) as a sort of expression of chemistry and physics rather than some special thing beyond that. Don't really know how to explain it, since it wasn't really a "oneness" with nature/the universe as some describe, but more like myself being removed from my own human viewpoint and viewing life/humanity as it really is, which in-turn allowed to me comprehend the incredible brevity of our existence, and also our own inextricability from it, rather than being somehow removed (as I think our brains are naturally wired to make us feel, since it's more "comfortable").
Of course, I'm also an extremely skeptical person, and I've felt plenty of crazy, revelational things on various drugs that I've later mostly attributed to the fact that I was, you know, tripping balls, but that DXM one always stuck with me, if only because I've been able to continuously view the same concepts through a more rigorous (and sober) lens and see them remain, as opposed to me being on shrooms and looking at a lamp being like "oh fuck, the light, it's...bright! That's why people believe in angels!" (yes, that "revelation" actually occurred to me).