Sounds like it might be the stuff that Bruce Parry tried out with one tribe... the Matis I think.  It was either in 'Tribe' or 'Amazon', probably Tribe as that was the first time he met them.  He was given puncture wounds to the arm, venom smeared on the wounds, then he puked, then as soon as they took the venom off his arm he was elated at not feeling poisoned anymore.

I saw another documentary once when a botanist in search of aya was given what seemed to be the same thing, then went off hunting for armadillo.  Sorry I forgot the name of the programme.  It was a strange one because once he found the aya shaman through his fixers, both the shaman and the French fixer obviously couldn't stand him and both criticised him to the camera as a 'spoilt brat'.