If you drop it in salt water while it is on, it is most likely toasted.
If it was off, you might be able to save it:
1. Leave it in the water. If you dry it out now, the salt will be inside (salt=bad).
2. Get it into fresh water ASAP.
3. After a fresh water rinse, dry it as others have shown. (The rice trick was new to me.)
I have seen this work for portable radios. All of this was before cell phones... before the internet... my hair was longer and didn't have any grey in it.