We recently tried out Rustoleum’s NeverWet, a new spray-on hydrophobic coating for all kinds of surfaces. It's not recommended for electronics, but we decided to (safely) experiment with some circuits!
Applying NeverWet to electronics
NeverWet is a two-step spray and is a respiratory and skin hazard, and it's flamable. We prepped our well-ventilated outdoor area for overspray, set up a fan pointing away from the body, and put on gloves.