I have read all posts and am still baffled. I have a Watco pull and turn tub drain. I am certain there is no set screw. There is no way to put a screwdiver on the top of the brass shaft that the drain plug rides up and down on either. It's just a plain old mushroom head brass rod.
How do I get the ##%% rod out? What about grabbing a holt of it with vice grips? I see no way that it comes out otherwise!
I am not a master plumber but I have worked on a lot of plumbing and I am about ready to take a crowbar to it and forget about using it as a tub anymore.