The handwarmer application is an old and a good one. (Try THIS with plastic hulls!)

This technique worked best with highly-waxed hulls like Federal's. As I recall, WW hunting hulls were not quite as good at this application and their target loads did even less well. Rem/Peters hulls tended not to be very good for this applicaton at all.

No, a collet sizer most likely would not be of much use for swelled hulls. The sizer I was referring to was a sizing chamber that sized the whole shell.