For a matte/satin finish, the Scotch-Brite belts excel. Sand to 400 or higher and get all the scratches out. Then, use a medium or fine Scotch-Brite belt and put on the satin finish. Be warned, if the scratches are still there, they will show.
On general use knives, I put the final edge on with a 120 grit belt and then buff off the wire. On filet blades, I follow the 120grit with a 400 grit, then buff the wire off. I do the final edges on all kitchen knives by hand. Buffing a sharpened blade can be dangerous and also ruin the edge if you don't know what you are doing, so the better method for most makers is to finish the edge on a fine stone and a leather strop.