My old SWR bass amp has been put away for a couple of years. Now, the pots are very scratchy and the volume cuts in and out. This had happened years ago and a tech cleaned the pots and all was ok. Now I'm alot more confindent working on amps, since I've gained some experience. What do you use, and how is it done? I've been told WD-40 is a big no-no. I suppose any Radio Shack might have a product that would do the trick, but what? Thanks in advance guys.