hey, I just noticed this is one crazy to another
First I would put it in a warm, sunny spot not over 100F for a couple days, a dry area would be best so evaporation rate is maximized. Not too direct sunlight or it could melt the case or something inside, most electronics don't like over 120F. After all the moisture dries, you may have to turn the rheostat type knobs up and down a few times to clean the contacts in case mineral deposits were left over, or use contact cleaner spray on each rotary switch if the few rotations don't clean the contacts.