How to fix water damaged iPhone 5c?

Hi. My phone got wet when I went kayaking in a canal (brackish water) when I capsized. When I got home I immediately put it in a container of rice. After about a week of sitting in rice I attempted to charge it. After charge the screen remained black (and unresponsive) with only the rear camera flash staying permanently on as well as the proximity sensor (little red light next to front speaker). Unplugging the phone obviously runs the battery flat and the flash turns off. That was roughly three weeks ago. However inspired by my brother's phone's miraculous recovery (turned on after being dropped in water months ago and working good as new) I reattempted to charge and fix my phone. Upon plugging my phone in nothing happened except the phone heating up quite a bit. Having now replaced the battery, still the same happened. However after removing the plate protecting the connections where the screen connects to the logic board, (It felt the hottest to touch and so I removed it) the phone whilst still being unresponsive appears to have stopped heating up (mostly, its still a little warm but no where near as much) and the proximity sensor has come back. I am considering soaking the logic board in alcohol but am otherwise as a bit of a loss. Any suggestions would be greatly appreciated. Thanks :)