I don't understand this rice solution or who made this up but in causes more damage than good cause when water drys on electronics it corrodes. Like why would you put a £400 phone and think rice can fix it.. It's beyond me..
The phone needs stripped out the motherboard needs all the guards taken off and washed with 99% alcohol then let dry and rebuild phone. If your display isn't going it could have blowen the backlight or just the screen..
You would be saver just giving to a repair shop cause if your using rice then it's not the job for you