Spilled water on xbox 360!! N n?

Okay so my dumb but dog spilled a glass of water on my brothers xbox 360 and he didn't notice it for a while like about 5 minutes and than when he did notice it he freaked out took it out unplugged everything took off the cover and every thin removed what I think you must have to send into Microsoft the little stciker under the faceplate. He didn't open actual xbox. He dried it than plugged it in and it started of than the power blinked red a few times and xbox turned off. We let it air our a few days and than turned it back on. It worked but it is pretty slow and feeZez up a lot. Is also getting really laggy on xbox live. What should he do. And what was the sticker he took off