What does the torturous thumb screw do?

yes

Push up on it turn ninety degrees and pull.

because i farted :D

of course it is the iron screw because it is made up of minerals that rust faster then metal

Usually with the tire iron/wheel wrench included with the jack. If that is missing, try a ratchet with a socket that fits. I've even used a screwdriver to twist it half-turn by half-turn.