iPhone 6 submerged for 18 hours and it works!
I just have to share my success in hopes that it helps someone else! My son dropped his 3 week old iPhone 6 into a creek while going fishing. After searching for several hours, darkness prevented us from continuing and we came home. The next morning, I went back and found it, face up in about 3 feet of freezing cold water. The screen was black and I had no way of knowing if it was off or on. I just didn't touch ANY buttons to be safe. I stripped off the Otter Box Commuter case (it's very snug) and let the water drain out....it was ALOT! I left on the glass overlay that we added for extra protection. I got it home, wrapped it in a single layer of cheesecloth, and placed it in a ziplock bag of dry white rice.
I immediately went to purchase a large container of Damp Rid. When I got home, I removed the paper cover off the tub of Damp Rid and placed in a large garbage bag along with the now OPENED baggie of white rice with the phone inside. I sat the entire bag on a warm heater vent on the floor of my office. After 3 days, I added Damp Rid directly to the rice bag and still leaving it open, resealed them both in the bigger garbage bag. I left it to sit for 2 more full days.
Moment of truth: We plugged it into the wall. Immediately the red battery sign turned on saying the battery was dead. 10 seconds later the Apple sign came on. Notifications started alarming. It started charging. It looked perfect! There was a SLIGHT watermark under the screen that faded after a day or so, but this phone survived 18 hours underwater with NO problems. No microphone or camera problems. Nothing. Truly a miracle.
Good Luck!
iPhone 6, iOS 9.2