The issue is THC not a hallucinogen, if we are seeking altered states this not enough. Not against using various substances for system and music enjoyment, but I see the goal of high end audio to induce the altered state without the need for these substances, this what I mean by sustainable. I'd suggest medicinal/pharmaceutical substances not sustainable in that they can severely impact our physical and/or mental well being. I know this from first hand experience having gone through drug rehab, and I've know far too many casualties who never sought rehab/therapy. Using mind altering substances on a regular basis can be difficult, as they say moderation is the key.
You are right about drugs !
I did not use THC save one time or 2 a year...
My ASC experiences are linked to music listening in good acoustics conditions...
Some music can be very powerful....
I use some specific album since 20 years for example to relieve stress and it is as powerful as a drug...
To merely relax i had many other choices...
To accelerate the thinking or creative process as writing, nothing beat Bach or Choral music for me...
To enter into more subjective moods i can use Jazz or Liszt or Scriabin or Chopin etc ...