The 'way in' to sealed square shafted selector switches is often, as you
have discovered, the gap around the shaft. Decent switch cleaner /
lubricant
seems to have good creep and penetration characteristics, and a good
squirt
up the shaft gap, will, in most cases, find its way into the switch body,
and do a decent job of restoring contact.

Arfa


I've been using an attachment for guitar pots that screws atop the pot
and allows the cleaner to squrt down the shaft. Saves a lot of time in
some cases and can be used on anything with a similar pot.

That's interesting and very useful sounding. Where'd you get it ? Any ref
with a piccy ?

Arfa