I don't know quite what to make of all of it. I realise that the man's (Graham Hancock?) primary point is to emphasize that it should be the right of an adult to alter his frame of view or his consciousness. This I can agree with completely. I have always felt that as long as it doesn't hurt anyone else, then one is entitled to put whatever one wants into one's body, and that's nobody else's business.
However, I'm not sure if I agree that this Ayahuasca brew or any psychedelia-inducing substance is necessary to bring about a basic change in someone's mindset. No matter the potency or composition of the substance, the "high" will ultimately be all in the head of the user, and will be inspired by his own thoughts, memories and predispositions. I sincerely doubt that such a substance exists which can make any person think along the same lines. If there was, our governments would be all over it.