I'm clearly missing some key context here, judging by the other two comments seeming to know what you're talking about, but I'm none the wiser about what's the deal with him and… Ayahuasca? which I'd never heard of before this thread.
There is some chatter about trend among techies drinking Ayahuasca and suddenly becoming a different person. I was curious if it could be related to the events that unfolded unexpectedly.
First it makes people purge (vomit profusely) because the MAO enzymes normally break down the psychoactives in the stomach, and it reacts violently when the enzymes are inhibited with MAOIs. It's likely a reaction to something else in the plant because the psychoactives absorb into the stomach before they throw up.
The technical name for what happens next is "full disassociation" which can best be described as the brain disconnecting from the sensor organs and then hallucinating whatever it wants in their place. The actual experience people have varies all over the place. Lots of trip reports of people seeing god, or aliens, or seeing their life flash before their eyes.
It's popular among the Silicon Valley crowd in general from my experience, but specifically the ritualistic experience in the Amazon. Freebasing DMT isn't as popular.