I haven't used any coatings on my boards in 6 years, but this year I bought a bottle of Corrosion X for guns. I called the company that makes the stuff and the lady said it's essentially the same thing (electrically safe), and it comes in an applicator bottle with a fine tip rather than a sloppy spray bottle/can.
I'm not interested in drenching my boards. I just want to use a bit in my "waterproof" connectors which aren't always waterproof, you know.