It’s one of the messier options but it still works well. The switches in my logitech g604 have been bounce free for over a year now after hosing then down with WD-40. That’s longer than any of the warranty replacement mice lasted.

Deoxit leaves a residue, too, that will stain clothes. That residue is what helps the contacts from oxidizing again in the future.

Yeah alcohol works well. WD-40. too.

That is kind of just how non hall effect thumb sticks are. But I’ve had great luck with Deoxit D5. You have to take apart the controller so you can squirt it directly into the switch itself but as long as it’s not a mechanical problem like a weak spring, the Deoxit usually gets it working like new.