Rice won't reverse corrosion, rice won't fix your phone. Rice is for eating. Avoid adding power to the damaged device, it can cause more corrosion or damage to the failed parts of the logic board.
When water gets into a device you need to take it straight to a repair store. Look around & you may be able to find one that can get it to a state where you can recover data. Apple will offer to recycle the device & may give you a discount on a new device (very unlikely). Water damage is not covered by the warranty, if you have Applecare you could try to use the accidental damage replacement fee to get a refurbished device, I believe water damage is also not included in that plan but you need to ask at an Apple store.
Third party repair stores may help you recover data but fixing a water damaged device is difficult & many companies will avoid it because it is difficult to guarantee it will not fail again soon.
Your best option is to buy a new device if you have a current backup, otherwise ask for quotes from third party repair stores near you.