At this point, I strongly suggest that you stop using this iPhone and keep it powered-off. Whether or not, you get an error, is not important.
Next, take the phone to your nearest Apple Store's Genius Bar or an Apple Authorized Service Provider to have them take a look and provide you with your options. Don't waste your time placing it in rice or using a blow dryer as neither of these will actually help. Remember, even if you can get all of the liquid removed, there is a good chance that minute residue will remain that can potentially cause short-circuits further damaging the phone.