Wow.. even the pinpointer. ...What is a guy to do? Even tho I havent submerged my vibraprobe.. makes me glad I went with it. At least now the new garrett and makro are coming as waterproof. I just know last Saturday when I was fighting the barberry bushes and briers, the battery died. I take a spare set (2 for detector and 1 for pinpointer) all the time. But OMG I didn't realize how much the sensitivity came back and how strong the notification vibration was after a battery change.
Rubbing alcohol might help if you are daring enough to take the control box appart. Or contact cleaner if you can get some. The stuff I use is Pow-R-wash. My guess is that board is attached to the display and can only be separated by de-soldering. That means the plastic parts attached might pose a problem for heating up past around 176F. Panels get baked at 220F for 4 hours to remove moisture before rework. Just the concept to elevate temperature, you can try to dry it out quickly. I think it needs to come apart, regardless, to dry out inside. You can't just leave the box closed while expecting for it to dry.