Oh I've been crying all morn over a scenario just like this! I dropped it in a mud puddle last night where it stayed for about 2 hours. It was freezing temps out. It had a rubber case and screen protecter on it and was stil on when I found it. I was able to use the touch screen but the buttons were overly huge on screen. I pulled out the battery and shook it out and then sadly put it back in and it wouldnt turn back on. I took it out again and have had it in rice for about ten hours. The water damage indicator on the inside is still white with red x but the one on the battery itself is all red. Is there any hope?? I've only had it for less than a month and don't have insurance on it.You're not SOL unless you put the battery in too soon and power it up and end up frying the chip.
3 days is the recommended length for keeping the battery in one bag of rice and the phone in a separate bag of rice. Do not put both in the same bag. Make sure they are completely covered with rice. Giving the bags a little shake here and there every so often helps too.
I've helped out countless friends who have had this issue. Worse was a co-worker who dropped his Droid Incredible in a puddle of dirty cold water at work (natural gas company) and it was in the water for 8 hours. Another co-worker found it and gave it to me and I automatically knew who it belonged to. Gave it back to my co-worker and told him exactly what to do. Instead of 3 days I told him to leave it in there for 5 to 7 days just in case.
He still has the same Droid Incredible and it's working just like it never was in the puddle of dirty cold water.