Could be just further corrosion as well. Water damage is nasty and unpredictable.

 

Not that you had one available, but if you could have stuck it in a vacuum chamber for a good long while, all of the water vapor would have been pulled out of it.

Not hard to make one for future washer emergencies
Just get a brake bleeder vacuum pump from Harbor Freight and use a glass jar with a tin lid on it, a hose to a nipple and you are ready to go.

Pre planning ya know......

I'm almost there, my wife uses a vacuum pump to suck the air out of her leg prothesis. Vacuum is what holds it on so it won't fall off when she walks.

See, a bright side to everything, you just have to be willing to look.

Momma didn't promise me a rose garden and a perfect wife. I just took the luck of the draw.

 

Wouldn't the vacuum be painful? 1 bar of negative pressure on human flesh is quite a lot.

 

Duh, I just "assumed" all would know that only the cellphone is inserted into the jar to under go the vacuum process.

The vacuum will remove all traces of moisture. Leaving a totally dry interior surface. just a tidbit to keep in mind.

time to leave it in a vacuum would depend on how much water vapor is in the phone.
just damp, about 30 minutes
Wet, a lot longer, all droplets must disappear, so don't wipe off the surface. Leave some drops there to give a visual indicator of "how dry I am" from the phone's perspective.

Same exact procedure is used to remove all traces of oil and air from an air conditioning system's cooling lines and compressor.

 

You can download "lock screen widget" from the market. Then you can use the widget to turn the screen off and use the "home" button later to get the screen on.

This would negate the use of power button.