I usually remove water spots with a micro fiber and 91% alcohol. Sometimes I just use my breath. I have never had good luck with cleaning chemicals. I will use Pec-12 on the surface of prints. If you have embedded dust in the emulsion then rewashing is the way to go.

I recently cleaned a friend's Polaroid 55 negs, which he had set down on a towel when wet, with a cotton ball under water. They came out fine and I couldn't see any damage when I scanned them.

YMMV