how much/what part of the circuitry gets wet and how much/what kind of corrosion subsequently occurs. Absolutely, DO NOT TURN IT ON while still wet; the moisture will, odds are, short out some portion of the circuitry. Dry it as rapidly as possible, consonant with not doing further damage; i. e. VERY low oven w/ the door open or putting in direct sunlight after draining/shaking as much moisture as possible. You MIGHT be able to save it and its worth a try, unless you dropped it into sea water!
from an ex-Air Force trained radar tech from back in the days of discrete component systems, who retrained into digital professional audio equipment support. Your mileage may vary.


Edit: absolutely, take the battery out as soon as possible, dry it physically, and very gently swab out the inside/whatever you can access, being very careful not to damage anything in the process.