Best way to clean electrical switches and connections?

[donnie5336]

Working on a 1994 Marathon for a friend, and the battery compartment is very very dusty and dirty. Brand new batteries in the cart and it runs fine but the F/R switch, speed controller and motor areas are very dirty. Compressed air does little to no good, it's stuck on there. So what is a good way to clean these areas? Is there some spray electrical contact cleaner that works good for things like this? I know water is a no-no in these areas.

On a side note but I believe it's somewhat related, the F/R switch is a little stubborn sometimes. It works both ways, and you can hear the click in both F&R but sometimes switching from F to R it won't go, and you just bump the kick panel right there by the switch and then it works. Is this most likely a bad contact somewhere, due to the dirtiness?