As promised in the Claypen chat today here's a pic and a little info on how I (finally) made my sanding tool:
Ever since I saw the *Scumbuster* mentioned as a great sanding tool, I've had this idea on how to use an electric toothbrush instead, since Scumbusters isn't an item sold in Denmark (as far as I know).
I recently came across a battery powered toothbrush that might do the trick (and was cheap, too), bought that and two 2-packs extra brushes.
I wrote a grit number on each of the five brushes with a permanent marker and with a leather punch 1/2" circle I punched out little dots of the sandpaper in five different grits and glued them on the bristles of the five brushes using a hot glue gun.
Note: Put glue on the bristles and then the dot of sandpaper on top to make sure it gets a good grip - the little glue you can put on the dot of sandpaper will not be enough to keep it adhered when you start sanding.
....and it works like a charm - wet or dry! It's great for small items like beads/jewelry and I think also for hard to get to places on sculpts, but might be a little tedious for larger things, but then again it might not. At least it saves your shoulder and wrist a lot of work. (not to mention your fingertips and nails)
When the sandpaper is worn down just rip it off and replace it. I keep my lil' dots in zip lock baggies, as you can see.