There's a bit of learning curve in order to get really good results, so I'd recommend "Change your mind and keep the change," by Steve and Connirae Andreas, or "An insider's guide to submodalities," by Richard Bandler and Will Mcdonald. It isn't the main thrust of either book, but you need to learn some terms to understand what they're talking about when they explain how to do it.
This comes from NLP and Design Human Engineering, which is part of what Robert Anton Wilson is doing these days. It involves hypnosis without all the hocus pocus -- and actually, the drug states are just a snowflake on the tip of the iceberg. Personally, I'm playing around with the idea of nanotime these days. (See Bart Kosko's book of that title.)
>> For even more, certain hypnotic techniques can revivify any drug state
>> you've previously experienced at will. And when you've mastered that, you
>> can start combining drug states, then combining combinations.
>Wow! Do you know where I can get info on this ?