What tools and chemicals do you use to clean electrical contacts?

What do you use for buttons on things such as remote controls? (I
have a kitchen timer with buttons that have to be pressed several
times.)

What do you use on battery contacts? (I know to use white vinegar to
clean up leakage from alkaline battery leakage.)

Thank you in advance for all replies.
--
Whenever I hear or think of the song "Great green gobs of greasy
grimey gopher guts" I imagine my cat saying; "That sounds REALLY,
REALLY good. I'll have some of that!"