Dry and try. If it's gone, no harm done. It could have short-cirquited already - but realistically, if you can charge it after drying it, it shouldn't damage the camera. I wouldn't put it straight into the camera, though.
Same - rice in a ZipLock bag. Get all the air out (or as much as you can) shove the batt deep in the middle so it's surrounded on all sides. Leave it in there for about a week. I almost lost two batteries when I got soaked in a downpour and couldn't move from my shooting position this summer. All ok and I kept it in there for about 10 days.
Some people here have a tradititional airing cupboard (where the hot water cylinder lives) and some don't, hence my question. An improvised shelf above a radiator would work just as well - the gentle warmth is the important point. I believe the rice method works well too.