Here's what you are looking for : http://swifts.co.za/herschell/retail/aerosols/electronic-cleaner-spray
Builders Warehouse stock it - think around R50/can and a can should last a while. Unless you are a Gear Junkie, then maybe around a week or so ?
There's also Spanjaard Electocleen - smaller can & slightly pricier - Communica/Yebo/Mantech usually stock it.
I've used both, same stuff really. If the pot's really old or really dirty then there's a chance it might loosen the physical feel of the sweep - though I've found that's a exception and not a rule.
If you have to replace the pot then the Dimarzio ones are the best I can easily find (I read that they are CTS repackaged).
Otherwise the cheaper alpha pots (gear junkie/blackbeards den) are functional - I did some reading on the topic and I think the major difference is variance of resistance . You pay more for the pot being closer to the advertised value ~ Alpha pots can be up to 20% more or less of the alleged resistance where the CTS allegedly are 5%.
Also longevity, the 9 yr old CTS one's on my strat still feel new - while the superstrat has 4 yr/old alpha's and one feels a bit 'loose'.
YMMW!