Santa,
Cleaning them *may* temporarily fix the problem, it may not as well.
If you go to CH products website, go to support, and tell the via their webtool what your problem is, and tell them the potentiometers are no good. They will send you new ones in the mail. Took about 5 days to get here, I imagine it may be something like 2 weeks to get to your neck of the world.