All I can remember is that I didn't have to remove it to drain the radiator into a pan, no recollection of how many turns I gave it. Since it's a plastic plug in a metal object there's no galvanic corrosion to make it stick and different penetrating oils might even make the plastic brittle. I replaced my '01's original radiator a few months ago and the plug cam out with almost no effort on a short-handled ratchet. I've only had the car 2 years so no idea how long it was untouched.