Doors of Perception
I do not see the connection but we each percieve through our own 'eyes' and this does warrant a response.
"Cleansing the doors of perception" is a quote from a William Blake poem, which Aldous Huxley used to entitle his book on hallucinegenic experiences, "The Doors of Perception." First, we need a bit of 'geneology.' Krishnamurti and Aldous Huxley were very good friends. Aldous Huxley was also good friends with Timothy Leary. I was a close friend of Krishnamurti and a friend of Tim Leary but never met Aldous Huxley.
Krishnamurti was opposed to the use of psychedelic and psychotropic substances. He felt they were unhealthy and unnecessary. I was a child of the sixties and, at that time, would select my daily version of reality, by concocting my various chemical coctails. Over time, I learned that I did not need drugs to alter my perceptions of reality. I will say that drugs 'opened doors,' in the sense that they showed me that separate realities can be perceived.
To me, Aldous Huxley, in "Doors of Perception," answers best "Reflecting on my experience, I find myself agreeing with the eminent Cambridge philosopher, Dr. C. D. Broad... "The suggestion is that the function of the brain and nervous system and sense organs is in the main eliminative and not productive. Each person is at each moment capable of remembering all that has ever happened to him and of perceiving everything that is happening everywhere in the universe. The function of the brain and nervous system is to protect us from being overwhelmed and confused by this mass of largely useless and irrelevant knowledge, by shutting out most of what we should otherwise perceive or remember at any moment, and leaving only that very small and special selection which is likely to be practically useful."...
[The valve of perception] ...As Mind at Large seeps past the no longer watertight valve, all kinds of biologically useless things start to happen. In some cases there may be extra-sensory perceptions. Other persons discover a world of visionary beauty. To others again is revealed the glory, the infinite value and meaningfulness of naked existence, of the given, unconceptualized event. In the final stage of egolessness there is an "obscure knowledge" that All is in all - that All is actually each. This is as near, I take it, as a finite mind can ever come to "perceiving everything that is happening everywhere in the universe."
My experiences with drugs have awakened me to the fact that there is a very fine line between schizophrenia, hallucinogenic schizophrenia and some intense spiritual experiences. While engaging in such experiences, I try to keep this in mind.
I agree with Krishnamurti... pychedelics and psychotropics are unhealthy and not necessary. And, I can add that they no longer have an effect on me; neither do stimulants nor narotics.