Real answer because I'm procrastinating:
They realized pretty quickly that the psychedelic drug avenue was a bust. The reality is that hypnosis works a lot better than we're lead/allowed to believe, but only in people who are already susceptible to dissociative episodes; and dissociation is a defense mechanism that arises in response to psychological trauma. I'm skipping over a LOT here but basically they figured out how to make so-called Manchurian Candidates, but the process boils down to torturing and traumatizing somebody so thoroughly that they develop dissociative identity disorder as a defense mechanism, and then using hypnosis to "program" the "alter" personality. It is very possible that the process has advanced beyond that because this is the state of the program in the mid-to-late 70s, but that's what's been leaked thusfar. This has been used to create "assassins" (actually patsies/fall guys separate from the actual triggermen for the sake of reliability) like Sirhan Sirhan, John Hinckley Jr, Mark David Chapman and fuckin uuuh that former Mansonite that tried to shoot Ford, but also sex slaves, "super soldiers" as part of the Phoenix Program, and serial killers (many of whom were also fall guys for larger groups, but this is deep in the weeds at this point).
A tangent to MKULTRA is something called depatterning, which initially involved administering barbiturates to keep subjects asleep for 20+ hours at a time, playing distressing audio recordings in their sleep, and subjecting them to electroshock. This would essentially "erase" their identity and memories, regressing them back into a blank slate to be retrained. I can't understate how thorough and fucked up this was, I'm talking total incontinence, mind of a newborn, had to be toilet trained and taught to walk again. This was iterated upon and basically they figured out you can achieve a comparable regression without drugs or electroshock just through isolation, sleep deprivation, sensory deprivation and stress; this evolved into KUBARK, the "enhanced interrogation" playbook circa Guantanamo. Once again, the protocol has likely advanced in the proceeding decades, we just don't know yet.
Basically the only use they found for psychedelics was as a way to distract would-be political dissidents by hijacking the counterculture and keeping them too high to pose a threat.
So if you want to be a useless hippie, yeah, drop acid and listen to The Doors. If you want to be a sex slave or a serial killer, get severely traumatized and hypnotized. If you want to be a pants shitting retard and start your life over, take a macrodose of phenobarbital and listen to recordings of rabbits being killed and chew on an electrical cord repeatedly. If you just want to go halfway and be mentally and spiritually broken, spend a week in a blacked out room with no light and no clock and speakers that randomly blast thrash metal at intervals less than an ultradian cycle.
Hope that helps.