PCB Board drawing high current when little bit of liquid gets into it. How to debug the board?
First remove the battery if it's attached to this board. Bake them for about 30 minutes at around 40C-50C (maybe check data sheets for temperature ratings but this should be okay). This should remove any moisture. Let them cool down and then perform your current consumption and functional test again.

In the future, conformal coating should help if they aren't coated. Also, maybe seal up the enclosure better with some epoxy or silicone. You could also if there's a place/room add or zip-tie a moisture absorbing packet (silica gel) to the board. Water/moisture usually finds a way even if you don't think it's possible.