Here are better primary sources:
The Johns Hopkins Study: http://www.hopkinsmedicine.org/Press_releases/2006/GriffithsPsilocybin.pdf Commentary: http://www.hopkinsmedicine.org/Press_releases/2006/GriffithsCommentaries.pdf
"How can I be more rational from a drug?"
In the short term, ingesting sugar will boost your capacity for handling complexity.
"I doubt a psychedelic experience can help me optimize my current utility function better than my sober self. How can I be more rational from a drug?"
WTF, dude? Not everything in life is about imp...
David Stove also talked about it a bit (not focusing on the transmission part but more on detection) with "What is Wrong with out Throughts?" ( http://web.maths.unsw.edu.au/~jim/wrongthoughts.html ). I'm not sure there is a good solution, as it is almost impossible to know whether or not you are in the grip of some irrationality.
To give an example, it is conceptually easy to kill germs - bacteria simply can't handle wide swings in humidity, temperature, acidity, etc. Washing hands with soap and hot water, cooking food, using bleach, etc. are ea...
There is a difference between rationality (optimal decision making based on the known facts and a set of value-weightings of possible futures) and the value-weightings themselves. It strikes me that eating the peach would quite probably alter how much you would value particular possible worlds, but I find it much more difficult to believe that it would alter your ability to deal with complexity (predict the future).