From a 2008 DKR book 'What Makes You Not a Buddhist'

Quote

There must be infinite ways to wake up from this sleep. Even substances like peyote and mescaline might give us a vague notion of the illusory aspect of "reality." But a drug cannot provide total awakening, if only because this awakening is dependent on an external substance and when the effect of the mescaline is gone, the experience is gone as well.

Suppose that you are having a really bad dream. All it takes is a flicker of realization that you are dreaming to wake you up. The spark can come from within a dream. When you do something anomalous within the dream, you may be jostled into realizing that you are asleep. Peyote and mescaline can spark a short-lived realization by revealing the power of the mind and the imagination. Hallucinations help us temporarily recognize how tangible and believable illusions can be. But such substances are not advisable because they provide only an artificial ...