I have a bunch of flashlights with creaky O-rings. Is there a general lube that's safe to use on all of them (I don't want to think about which ones are Viton and which ones are butyl and who knows)? Preferably something I can get at a local hardware store in a tiny little tube. I don't want to have to order it from somewhere (shipping costs) or buy a big bucket of it (I just need a tiny dab on each O-ring).