[Arran]

Don't use silicone or teflon based lube in a switch, that may gum up the contacts and then you will have to take the switch off again to get it working. Likely the WD dissolved some old grease and crud from the contacts or the mechanism, this is a common problem I run into with farm battery radios that have sat around disused for decades, I often take the whole control apart and soak the parts in mineral spirits to get the old grease and oil out.
Regards
Arran