Fascinating stuff. Very much like in Aldous Huxley's "Doors of Perception"... Now of course I've heard people going to the shamans in South America but I never got into experimenting with drugs in my own life besides alcohol (too "square" for that in college I guess...) The first I heard of he substance DMT was only a few months ago when I started meditating and having visions/hallucinations. I searched the web for more info about that and came upon some of those sites mentioned above. I guess DMT is kind of a short cut, for instance like using sensory deprivation tanks, for getting what may otherwise take years of work with meditation.
If only you knew how bad things really are.