hi fai,
it would be better if you start your own question - that way we can prevent some mixup problems.
i'm not the biggest fan of putting a almost sealed device with a soldered power source into a bowl of rice - the water stays to long in the unit and the power could still be there - shorting a lipo battery could be dangerous - so disassembling is the only way. i usually desolder the battery while working on the logicboard.
the water residue has to be carefully removed with ipa and a soft paintbrush.