It seems kind of wrong that batters can put substances and stuff on the bat to grip it better, but pitchers aren't allowed to do anything to make their hands a little more tacky to grip the ball better. Put something out beside the rosin bag that will make the hands a little tacky but won't transfer to the ball, and eliminate the nonsense once and for all. If the ump suspects something, give him the ability to call for the ball once in a while and make sure it isn't being loaded up.