"wet" components
I do the majority of my flying on floats. The occasionaly "dunking" is inevitable. I've always disassembled the receivers, and just let them air dry. When dry, they either work, or they don't. Mine always have. I don't think it's a question of reliability at all. The servos - same, dis-assemble, especially the bottom cover of the case so the electronics can dry. I've had a few that didn't work after drying, but none fail as a result of being dunked and dried.