I had great luck with this tool, too. I think I used a 3/4" bolt, with two lockwashers inside the cup, one lockwasher and a big flat washer on the outside, then the nut. Three foot length of ABS pipe as a cheater bar.

I don't remember if it's mentioned in Sheldon's description, but I use the adjustable cup to support the socket wrench extension. I also once had a really stubborn fixed cup, but since I wasn't keeping it I filed a bunch of notches around the spindle hole and that helped the flat washer get a really good grip on it.