After many years of listening to people praise the use of psychedelics and other drugs for Dhamma development, I still find support of their usage for those purposes puzzling. While I don’t disagree that a person intent on having a peaceful and fulfilling human existence can benefit immensely from spiritual practices that include these substances, the Dhamma is no such system, so the collaboration would only contribute to the peaceful maintenance of the discrepancy of Being and the associated suffering. The introduction of these substances to the living body is an attempt to alter how one feels and perceives the various content of their experience up to an including the very existence itself, but since Dhamma is intent on uprooting that vey basis, no alteration could suffice.
What I mean is, the content of one’s Being was never the problem, but it is that Being is not understood as impossible to be there to begin with. Practice of the Dhamma gradually brings the proliferation of experience (that is pressed out into the content) together into a place that does not misinterpret the meaning of what is there. This begins with generosity and virtue, and carries all the way through to an understanding that it was always the craving that kept the view in the wrong order. Once that is understood and the craving is dried up - as we often read the arahants proclaim - it cannot return. So, even though psychedelics can bring a warming comfort to experience, it does not last since that condition depends on a togetherness of something that cannot remain together, and furthermore, it is the mistaken ownership of that Being - whether comfortable or not - that the Dhamma intends to uproot.
To practice with an enhancement of a sense faculty is to practice an embrace of suffering and its origin. It is a truce of sorts, and for one who is intent on a truce, there is probably no better method for doing so, but the suttas tell a whole different story. One of not needing an alteration of sense faculties, nor one of needing an alteration of content to what is more manageable for day to day living. The training builds up a capacity for endurance of what is displeasing through the non-doing of what is unwholesome, but that is only half the battle, if that. Within that endurance one must discern why it is actually craving, not the “things in the world” that is the source of displeasure, which means that there is no need to make the content more manageable. Indeed, a person would benefit from practice in a more wholesome setting, but it is always in one’s capability to not give into the pressure to act out of craving that they can see that the pressure, not only arises on its own, but that it is within that non-action that one can begin to take responsibility for the choice to give in to that pressure or not.
While psychedelics make the entire experience less pressuring, it does not contribute to one’s strength in enduring the pressure. That is a subtle but critical distinction: a depressurized space is certainly less uncomfortable, but without that immense pressure one can avoid responsibility for giving in to sensuality and thus avoid the pain of restraint, completely missing out on the opportunity to embrace the field of renunciation. That “opening amidst confinement” cannot be utilized if the confinement is not recognized in all its intensity. In short, relieving that pressure through sensuality, with or without a substance, instead of allowing it to build up naturally, is relieving and comforting, but also blocks the opportunity to leave craving with no outlet, which would eventually lead to drying it out and destroying it for good.
Not like it matters, but, yes, I’ve taken these substances on many occasions in the past, and found them to be very fulfilling. Nevertheless, that isn’t the point of the Dhamma (as described in the Pali Canon), so I’m of the opinion that using them is hindrance to development and should be avoided.