Be absolutely sure it is totally dry before you try anthing. Take off the keyboard. The screws are on the bottom. Remove the hard drive, optical drive, and battery. Disassemble everything you can. Remove the CMOS battery. It is wired in, under the keyboard. And be sure the memory is removed and put someplace to dry.
Then clean with a 50% solution of Isopropyl 91% alcohol to clean everything. Use very soft fibre free towels. Wal-Mart and others have them. The alcohol, being hygroscopic, will help remove the moisture.
Then
Dry it upside down in an area where there is good air flow for two weeks.
Don't use a blower or a hair dryer as they introduce dangerous static electricity, but a room fan will be helpful if not too close.
We have saved a lot of laptops that have had coffee and cola spilled in them. The worst damage is done when the computer is turned back on. Since yours was flooded, it may be too late.
The secret is to be sure it is totally dry. Then replace every thing and turn it on.
You may have a chance. You may have to replace some parts. It might be easier to replace the motherboard if it doesn't start up. They are around $80 on eBay.