Beware of cleaners also containing an oily lubricant which will, as Richard cautions, attract more dust into the control. This will work for awhile but then eventually degrade back to noisy again. Electrowash is a good dry-type cleaner that I've used successfully many times. It is basically an industrial product, available from well known vendors such as Allied Electronics or Newark, among others no doubt. I'm sure there are other products of similar dry composition.
