Another thing to watch for with equipment which uses ganged rotary switches whose wafers are of non-ceramic construction is that the wafers can wick up DeOxIt or similar cleaners and swell. They may be rendered useless.

Sparingly is the key here. Use the applicator tip of the bottle or a syringe to put a small amount of the 100% solution directly on each switch contact to be cleaned and swipe it up with a cotton swab after rotating the switch several times.

Then (as previous contributors have mentioned) rinse with alcohol.