I have heard of people depriving themselves from sleep for a long time and in the end they start hallucinating. Same seems to happen when one isolates himself into total darkness for a few days. Absolutely no light. Some African tribes use that method I once read. If I am correct it was in one of Graham Hancock ’s books.
I am not too keen on this methods so I stick to my changa
.
Quiet the mind and the soul will speak