Shamaic plants and psychic phenomena?

I've been puzzled by the psychic effects Shamanic plants induce, such as ayahuasca vine and psilocybin mushrooms. Many people experience entity contact and make realizations about their self and the world. I consider these plants to be "teachers" because they can show people the "other side", and lead people onto their spiritual paths, if used properly. What puzzles my mind is whether these plants effects are just random and happen to induce spiritual states of mind while also causing some form of schizophrenia, or if they actually have spirit guides associated with them and induce astral experiences and genuine psychic visions. I don't believe in the use of these plants very often at all, I see them as teachers, because they tend to open peoples minds to greater possibilities, and lead them to their sober path to spiritual fulfillment. I realize that talk concerning this topic isn't really accepted in this community, but I really didn't know where else to turn for answers besides myself. What is everyone else's view on the effects of these plants?

http://forums.astraldynamics.com/viewtopic.php?t=7988


I'm sure you can find other places in the web dedicated to this topic- we have gone circles in this forum about this topic and never get anywhere with it.