Pleas do no put your phone in rice. rice is for dinner. Just ask Trent at riceisfordinner.com
The device immediately has to have the power removed. Battery must be disconnected, dont try to charge it, and it must be disassembled in its entirety. The impurities in the water need to be removed. If you catch it in the early stages you can do this with alcohol. Otherwise there are checmicals and equipment required to do this properly.
Water damage is caused by electrolysis. That means step one is remove the electricity, step 2 is remove the impurities. By putting the device in rice, you dry the water, and concentrate the impurities. Even if it works at the time, it will progressively get worse. Just drying the phone is not enough.
If you don't get to it fast enough, the board inside the device can become corroded and damaged. At that point, you have to have the board repaired, and possibly even external components to the board. There is a link on my profile to find a local (or the closest) board repair tech to you.