Hmm…interesting, I got it to work. In r29268 it works and I’ve attached a .blend file. It’s a very rough leg/foot. In it, the toe bone is selected and some weight paint is associated with that bone in the knee area (light greenish color) and hip area (dark red color). After selecting the clean tool from the toolbox, there’s a few parameters for it below the toolbox. I checked ‘all groups’ suggesting it cleans all vertex groups. Then play with the ‘limit’ slider some - adjusting the slider to .220 cleans the knee area, but it has to be moved all the way up, .990 to clean the hip area.
I’ve been using 2.5 to make a character, and I gotta say I think the weight painting is vastly improved over 2.49. The auto-normalize is a great tool, and now this clean tool is another great feature.
PS - Was just playing with this a bit more, and cranking the limit all the way up cleans all vertex groups too much, they hardly have any weight paint on them at all… Looks to me like it’s not perfect yet…
weightpaint.blend (67.3 KB)