What happens is, the world is completely replaced, instantly, 100 percent, it's all gone. And what is put in its place, not one iota of what is put in its place was taken from this world. So its a 100% reality channel switch. They don't even retain three dimensional space and linear time. It's not like you go to an exotic place, Morroco or New Guinea. It's like reality is swapped out for something else, and when you try to say what it is, you realize that language has evolved in this world, and it can serve no other, or it takes years of practice. So what you're looking at is literally the unspeakable. The indescribable falls into your lap... You cannot say what's there.
From A Weekend With Terence McKenna
deoxy » chemical experiences of a hyperspatial nature