One major factor to consider about using drugs is that a large portion of the effect that a person feels after taking them is based on what the person expects to happen.
Yes, the major classes of drugs (stimulants, depressants and hallucinogens) do cause a predictable effect but, above that, the user's experience with that drug is mostly determined by what he believes will happen. Alcohol is a depressant but, because many people associate drinking with going to wild parties, people often become more excited when they drink. (Up to a certain point when the alcohol starts knocking them out.)
These people of the Amazon have a long cultural experience with the drugs they use and they know what to expect when they take them. If you took those drugs, you would not be able to predict how they would affect you because you have no experience taking them. You have no idea what to expect when you take them.
So, instead of enhancing your abilities these drugs might hinder you. They might stimulate you and make you more alert but they might make you so shaky you can't hold the camera still. They might make you sick. Not to mention the fact that they might kill you.
The bottom line is that, regardless of what anybody tells you, taking an unknown drug is like rolling dice. You don't know what could happen. You could roll a seven and win on the come-out or you could roll a twelve and crap out.
You'd be better off drinking a beer or smoking a joint.