I was handed a bag of parts (the DS had been partially disassembled in an attempt at drying it out) and told that rice wasn't able to save it. He had tried rice because everyone knows someone who thinks their electronics were saved by rice. Truth is, the rice did little to nothing at all and if someone's device came back on, they got lucky.
Here is the before and after photos of that DS.
The photo below is of two areas of the logic board where corrosion visible to the naked eye was blatantly apparent (circled in red for those who aren't sure what they're looking at). When water enters electronic devices, it brings dirt and dissolved minerals with it. Between the new outsiders and the gold, copper, and other metals inside the phone, you end up with a good environment for corrosion. Rice cannot stop corrosion once it starts and it cannot remove it.
Again, anything short of a proper cleaning will not remove the dirt and dissolved minerals the water washed into your device. Attempting to dry it out will not remove corrosion and gunk and will only make the corrosion and gunk more difficult to remove later. My personal preference (and that of Mendon iPad Rehab) is that if your device gets wet, you do NOTHING. Do not attempt to turn it on. Do NOT attempt to charge it. Do not attempt to dry it out. Your best hope at recovery is proper cleaning by a professional and I would rather receive the device sopping wet than bone dry and full of rust and corrosion.