To my knowledge Ted Kaczynskis experiences with MKultra didn't involve any substances. He just sat in a chair while some folks screamed at him trying to aggressively undermine all of his views.
Given that he secluded himself and wrote about his ideology for years like a comic book villain origin story, it's safe to say they took to too far, whatever it is they did.
Also, afaik MK tested lacing with different doses, and only the big incidents were disclosed. Why wouldn't you suspect drugging here too?
Edit: I also think this kind of thing exists in society today, but probably bought and sold on exclusive markets to modern lords and ladies.
Can you elaborate? I don't know what you're referring to.
I don't know if that is what is really happening and I doubt that it is, but I also don't know how to distinguish these experiences from that possibility.