We, at Florida iDoctor, do things a bit differently in terms of addressing water-damaged smartphones that make their way into our shop. You see, we are located in Palm Harbor, Florida and only a stones-throw away from the beach!
Of course, the first thing we tell our clients is IF your phone hits the water, to get it to us asap. Rice can work okay in a pinch, but the actual success rate using a bowl of rice is quite low if it were scientifically studied. Fresh water is bad for any smartphone. Pool water (with chlorine) is the next worse type of water infiltration. The most caustic of all water is salt water. Water with high levels of NaCl (salt) is very damaging to electronics due to the high level of corrosivity. Our recommendation is if your phone falls in salt water, to actually rinse it off under tap water in order to try and wash away some of the salt residual. We also ask them to remove the battery (if possible). One word of extreme caution...DO NOT, I repeat, DO NOT try and power on your phone to see if it still works no matter how tempting that may seem. You are certainly likely to short out motherboard components if current is applied through the circuits of a water-logged phone.
With that being said, once a client brings us their water-logged phone, the first thing we do is remove the battery. We then tear the phone down to the basic components (battery, frame, motherboard, cameras, etc). Once it is taken apart, we place the motherboard in an professional-grade ultrasonic cleaner using a proprietary dielectric cleaning fluid. This is one of the keys along with making sure the fluid is heated up. Once the board has come out of the ultrasonic cleaner, we rinse it off thoroughly with a deionized (DI) water. DI water is ultra pure and this rinse step will ensure that there are no trace contaminants on the board.
We then take the clean motherboard and put it into a container of desiccant along with all of the other components of the phone. We use a proprietary desiccant with the highest adsorption rate of any desiccant available on the market. This is super-critical so that you can wick away any moisture from the motherboard and the components as quickly AND EFFECTIVELY as possible.
We let everything sit in the desiccant for 24 hours to ensure complete moisture removal. Once complete, we reinstall all of the components and also install a NEW BATTERY (NOTE: We recommend never reinstalling the same battery once it has come into contact with water).
I hope this helps the readers of this great guide. We utilize iFixIt every day in repairing phones in our shop and therefore, we believe in contributing to this guide. If anyone needs further help with this process, simply let us know. Since our store is located near the Gulf of Mexico in Palm Harbor, FL we see water damaged iPhones in our shop every day. This process we listed here has achieved over a 74% success rate in restoring water damaged iPhones.