You don’t know whether or not things which render people who don’t even know they’ve been given them unconscious very quickly should be OTC or not? Really?
And about alcohol- it’s a horrible, horrible thing in many ways, including facilitating date rape (although nowhere near as easily as ketamine). And if prohibition hadn’t been a complete failure, I would support it continuing.
But I wouldn’t say keeping ketamine prescription-only has been the failure that prohibition was because otherwise we’d have a lot more Matthew Perrys and a lot more Bill Cosbys. Which is what you seem to want.