Most of the time he is out of the city in his rancho. You can contact Flavio via facebook he is very open man and has connections with the native tribes.
p.s
Yes, it's quite strange that he don't care about diet because it's not only for physical readiness but also for spiritual. I know that fasting can be really enlightening and is good for clearing the consciousness.
Speaking of facebook - give the below page a follow, I made it for promoting ayahuasca things in Paraty. It's been a bit quiet recently cos I've just been concentrating on my PhD, but you might find it interesting.
https://www.facebook.com/Ayahuasca-Paraty-Cura-do-Xama%CC%83-1107213262700883/