How to Clean the Drumtraks Buttons?

Drumtraks … Once I get the button caps off (and I have and can now see the plunger) the Save/Load/Song/Pattern/Tempo/Enter how do I clean them? I’ll get to the numeric keypad buttons too because they also only respond intermittently.

My question: is there a product I can spray into the buttons to clean them; maybe they’re not up to snuff because they are dirty or whatever?

Thanks!