Contact Cleaner, available at your local Radio Shack Just pull the knobs off the pots, try to aim the spray at the slit opening running the circumference of the shaft, spray, and then twist back and forth a few times to evenly distribute it! And of course, wait for it to dry before powering on.
i actually used that Radioshack contact cleaner and it fucking shorted my amp out until I cleaned it all off the board with alcohol. shit didn't dry up and just left some oily film everywhere. I COMPLETELY HATE IT NOW.
There are two types of contact cleaners, dry and oily ones. Dry is safe to use pretty much everywhere, and dries out almost instantly. And I have no idea about the oily type