Put your iphone together with some catsand (without the screen) in a plasticbag and close the bag carefully....after that put the plasticbag in the freezer.... maybe you have luck and after 12hours you have a new icecold iPhone :)
Quote from EdNem:
Put the mainboard into 2-propanol alcohol for at least 24 hours.
Then put it into fresh 2-propanol alcohol for another 5 hours.
Put it near (not on) a heater/radiator and wait another 24 hours.
(While waiting clean corroded contacts from the components in the housing/case with a toothbrush and 2-propanol - very gently, not like scrubbing your teeth!) :)
reassemble and pray. Good luck!