I use a very similar product in polishing small repair areas on musical instruments and they work great. The product I use is a foam construction and is only partially round, it reaches into really small corners as well as doing the flat spots. I wish I could tell you the manufacurer but I just go to the local place and grab it off the shelf, toss away the bag, and go to it!
I've never used them with a cordless, but use a variable speed 3/8" drill keeping it at mid speed.
Will