I've been getting the house ready for painting and like using the resin fiber sanding discs on a 4 1/2" grinder. That is tough stuff. Nonetheless it blocks up and you have to change it long before it is worn out. I've been able to clean it fairly well by sanding some stucco I have, but there must be some other method or product whose existence I'm oblivious to. What would that be?
Jeff