Try putting your phone in a bowl of rice and cover it up, the rice will eventually soak up the wetness of the phone. A old trick my friend told me about.

The rice trick does actually work but if it does not leave your phone on a radiator for a day.

I've dropped my phone in the sink and the toilet twice now and every time i don't touch any power buttons or anything, completely submerge it in rice and leave it in the rice in the boiler room in my house for 3 or 4 days before doing anything with it! Gives it a chance to completely dry out! If that doesn't work you could try taking it to a phone shop and see if they can fix it? if not you could try taking your phone apart completely and rubbing down all the components that have any signs of corrosion with isopropyl alcohol which you can pick up in your local chemists! After doing that leave it to dry out again and then you can try?

If none of that works i don't know of anything that will and i can't really help any more!