I had the experience of dropping my LG Dare in the toilet. I immediately took the back off and removed the battery, to keep the electronics from getting fried. I blew the thing out with compressed air (with the back OFF). I then dried it over a couple of nights with a dessicant in a big zip-lock bag. Again, the back was off, the battery out. Everything dried out perfectly, and the phone is as good as new.
Unless it was built to be waterproof, a phone (such as an iPhone) with a permanently sealed-in battery is NOT waterproof, and WILL fry its electronics - buh-bye iPhone!