I had the same problem, Decided to wash my dirty Iphone 5 (AT&T). Well after 30 min in the water I decided that was long enough.
First if you have a warranty USE IT! or call apply and they will replace it for a $225.
If your like me, then your warranty is no good. So go for it then! if not its just a $$$$ paper weight.
Never try to apply power when wet.
open phone and disconnect battery ASAP. (most likely your battery is no good) if it feels soft then it is bad. Chemicals in the battery don't react well when there submerged in water. I had to replace my battery.This will take care of the Flashing Apple logo.
Next I completely disassembled my iphone, to dry it out. You can use a heat gun or hair dryer! (be careful).
If your lucky you have little to no corrosion damage.
You can give it a shot. My phone turned back on with a bunch of problems.
no working Wifi
no working Cellular
no working front camera
no working vibration
Yikes!!!!!
So I had a paper weight or a ipod now. So I got bold and said lets do this. I stripped down the EMI shielding and gave it a nice scrub bath with Electronic cleaner and 91% alcohol. I had lots of corrosion this was a very necessary step. I also stripped the camera apart and cleaned it with alcohol and dried it out very well. canned air and a heat gun.
So this step fixed the
Cellular and the
camera / flash
... now the vibration is not working, I checked the motor with a AAA battery and it spins. Not sure if its bad or the connection that runs it to the logic board. will shall see, I order one to replace it. As for the Wifi chip, I think the water destroyed it. I tried to heat it up and make sure all solder point were good. So I have order a new chip to replace it. I will update you later and let you know how that went.
parts
Cleaner $5.00
toothbrush $free -used a old one I had
vibration replacement $3.00
EMI shielding $1.50 ( you dont need it)
rear camera $11.00 (don't need it) spare
Wifi\bluetooth chip $5.00
Oh, Apple has built a awesome phone. So much easier to fix then the iphone 4's. If you haven't upgraded do it.