I don't think you have much chance of getting it working.
Here is some advice from a mobile repair site:
Damage from corrosion and short circuiting commences almost immediately after a phone has been wet. Particularly when salt water is involved.
Here are a few tips to increase the probability of your phone surviving a swim.
1) Take the battery out of the handset immediately. Electricity increases the rate of corrosion.
2) Get the handset to us as soon as possible. Time is of the essence with wet phones. The longer the delay, the lower the chances of a successful repair.
3) Drying the phone out yourself. Often people will try drying out the phone themselves. They remove the cover and dry it out near a heater, with a hair dryer or in the sun. I've even had one guy try to dry it out in a microwave (Idiot. Needless to say the phone never went again). While this shouldn't damage the phone, and it may even appear to fix the problem, corrosion usually claims it after a while.
The only way to successfully repair a wet phone is to completely disassemble the unit, completely dry it out, remove any corrosion and use a corrosion inhibiting fluid to prevent the formation of more corrosion.