No lasting aftereffects? I think you'd have to turn this into an “and you don't remember afterward” scenario.

Indeed. Pain causes operant conditioning; removing the operant conditioning makes the pain be something very unlike pain. In fact, according to a theory I vaguely remember, the idea of pain is, to a great extent, a rationalization of aversion: "I don't want to do X. I guess I don't want to do it because it will cause me pain." If this vague rememberance were completely true, it wouldn't be pain at all. But this vague rememberance ignores the fact that we know whether we're in pain or not at the time we are or not in pain.