Simon,
I would like to say that Ayahuasca is drug as you say, but to many around the world who have tried it is a sacrament, and medicine. Call it placebo effect or whatever, people have been healed by it, and it is by no means a pleasuriable experience you get the shits(at least I did maybe once), you throw up, but seems to be cathartic that leads to some benefical changes for the good in many cases. This thing has been used as tribal medicines for many centuries by shamans. Many in the psychological community are interested in it just like other psychoactive substances.
But I see your point and will try to refrain from talking about alter states of consciousness from alcohol and other government restricted substances. But I have to honestly say it is going to be very hard I hope you can forgive the occasional mention of it from time to time.