You're just asking for trouble getting electronics wet. Moisture can wreak havoc with PCBs, and especially components, if it gets trapped inside one. Washing with a solvent like alcohol is even worse because it would dissolve the grease inside pots and switches, potentially redepositing as a thin film elsewhere. I've used alcohol and a toothbrush to remove flux on the bottom side at times, but for the business side of a board I'll use a brush.
Take your time, you're on the right track wish bristles and a breeze