The best method I've came to:
Go out and buy yourself a Kirby turbo sander (DO NOT use your good one, buy some old junky one you couldn't care less about), and place your sand paper in it. take a bottle of water and punch a hole in the cap, add some dish detergent to the water. connect the Turbo Sander to a wet-capable vacuum cleaner and go to town on that Kirby!
Works very efficiently.
