This is not my idea, I found it on YouTube. If you've seen the hand tool that you can get to sand clay you probably know that it costs about £60. Well this is an alternative that works brilliantly and will cost you less than a tenner. Buy a cheap electric toothbrush and some compatible heads, remove all the bristles with a pair of pliers, get some good double sided tape, some kids craft foam sheets then do this. Use the heads as templates and draw round them onto the craft foam, apply double sided tape to both sides of the foam cutout. Peel off one side and stick it to the de-bristled head, peel off the other side and apply a similarly cut piece of wet and dry, don't forget to mark the heads with the number of the grit paper used and e voilą you have a great wet sanding tool. Mine works like a dream, family went hungry while I tried this out!