apple recently started to take care of water damaged iphones. I dropped mine in the sink about a week ago. The phone started flashing white and vibrating, and i had a difficult time turning it off. When i did get it off I put it in a bag of rice for few days. This seemed to help a bit. However not completely.. I can turn the phone on and off, but the screen still goes through various sequence of flashing. I then proceeded to take the phone appart, I removed the screen carefully to notice there are at least 2 more water sensors on the inside, that are very easy to detect. Both of them were tripped. I let it air dry for a few days, and myphone is now functional. The screen still goes through flashing phases but i am able to text call, and all that other stuff. I will still most likely get myphone repaired. Apple will fix a water damage phone for $229 (canadian) im not sure on the price in other regions. But this seems like a fair bargane as a new ( regular) phone would run me about the same price.
Taking apart the phone is very easy and there are numerous instructions found online for doing so. Id say that is your best bet. Besides if you wanted to try and fiddle with the water sensors, then maybe you will have a shot by carefully replacing the stickers. dont forget the one in the headphone jack too!! good luck