I always use WD40. Years ago I once saw a complete mixer ruined by the use of so-called ‘switch cleaner’ on the pots….. it destroyed the carbon tracks because it dried them out completely and then they wore out immediately. I find that WD40 leaves enough oily residue on the track to avoid this happening. Just a VERY small squirt in tha back of the pot and work it a few times should do the trick. 
