For the record, the rice thing does NOT work. The rice absorbs an extremely miniscule amount of moisture unless the temprature is raised enough to have the water begin to break down the rice. Otherwise you could cook rice by letting it sit in a pot of water for a day.
The smarter idea is the little packets of Silica. As a fly guy, I keep all these and make my own drying powder for flies. Take them in the grain form, and do as you would with the rice. That would be much more effective at sucking up the moisture. Unfortunately, when I dunked my phone, that didnt work. What did was submerging the entire phone in 99% Isoprophyl Alcohol for 3-4 minutes. Shake it about, get the Iso in there good, and then take it out. It is non conductive and will evaporate very quickly, as well as taking any water out with it. Then again, now that I learned the Iso trick, I wouldnt bother with anything else. It is so quick and effective that there is no reason to sit around waiting for days. Dunk, blow dry it for 10 minutes, and youre done.