dmt, ayahuasca, bufo alvarius, kambó...are great tools if used wisely and given by experienced people that are beyond the "what a great shaman I am" thing. I did my last kambó with other people than my usual team. I passed out so quickly that they couldn´t hold me. I knocked my forehead to the ground. On another occasion I went to a temazcal. The tent was full of people and you could barely move. We were all sweating like crazy. Some were singing. Finally the lack of oxygen put me down. I lost consciousness and somehow my right foot got too close to the red hot stones. The guy in charge was pouring water on the stones, which produced the steam that gave 3rd degree burns to my toes. Nobody saw anything, as it was totally dark. When I returned to reality, 4 of my toes were open like a boiled sausage. It took me 4-5 months to walk normally again. I had other similar stories, so I´d say do it carefully, trust but verify, they are neither "dangerous drugs" nor "ancient sacred medicines" (both definitions are just word magic). Someone said "the world of spirits is not for a promenade. There´s a lot of work to do while we are here".