how can I repair water damaged iphone 4 on my own

My iPhone 4 was exposed to water for about 10 seconds 😮 (fell in a running shower) and was taken out, dried, etc. It was working absolutely fine, like nothing had happened. 30 minutes later however, the device failed to turn on and didn't respond to the charger. It is now currently submerged in uncooked rice, but it there anything further I should do to save my phone? Should I take it apart and keep it in the rice, will that cause any problems or further damage to the phone, etc? Please help, any suggestions would be helpful, it isn't covered under any warranty. I want to be able to save this phone. Thank you.