There's nothing Apple will do about it. There's some things people suggest, like putting it into a plastic bag full of dry rice so it absorbs the moisture but it doesn't necessarily work every time, it depends on just how wet it got.
If it happens to start working, though, Apple won't do anything if any other problems start. All iPods have water indicators inside (there's usually one in the headphone jack, and at least one other within the casing of the iPod itself that you can't see) which permanently turns from white to pink as soon as water touches it; when Apple sees this they'll just give you your iPod back because water damage isn't covered by warranty.