Rice does not do anything for your waterlogged phone except let the water sit longer which causes further oxidation. What you should do instead is take the phone apart. Disconnect the battery and remove all of the components from the logic boards. Remove the covers from the logic boards, as they hold in the water, and run them through a good ultrasonic cleaner for 20 minutes. When finished, submerge the logic boards in 99% iso alcohol for a few minutes to displace the water. Let these dry completely. That should stop the oxidation which is what will cause further damage.
As for the damage that the water is done, it may be too expensive to fix. There are a few companies that can look at the logic boards and make that determination or possibly recover your data.
Good luck and avoid the Rice