For cleaning — DeoxIT
https://caig.com/deoxit-d-series/
-- cmb_

I use and endorse DeoxIT, frankly! My can of D5 is currently sitting next to the Digisound 80, in fact. The stuff might seem like it's just basic "contact cleaner", but it goes a lot further than that...it adds lubrication to a pot that doesn't gum up after time, for one thing. And then, yep, it's got some anti-tarnish ingredients to help keep contacts from getting crapped up again.

It was so ubiquitous in Nashville back in the day that, if you ran into a crackly pot or intermittent switch with the resulting noise, everyone would be lunging for the DeoxIT can, unspoken rule-style.