It is not water itself that deals damage to a particular smartphone, but rather, it would be the minerals that will harm the handset’s innards. These minerals will short circuit the internal connections and result in the smartphone malfunctioning, but basically as long as there is no critical damage that happened, the handset will still be able to be “rescued”, so to speak.
Having said that, the first recommendation for folks whose handset has been dunked or gone swimming with the fishes would be to turn it off right away, in order to minimize the chance of a fatal short circuit – assuming one has not happened just yet. Reviveaphone’s Repair Kit comprises of a special liquid that will remove the handset’s internals from damaging minerals found in water. Using it requires some faith and for you to leave the handset in there for 7 minutes, before letting your handset dry for a good 24 hours. From there, keep your fingers crossed and try to turn on your phone.