Eh? I thought samsung was saying the 7 series was water tight? Or am I thinking of HTC or someone else?
The only way to really attempt to fix a wet phone is to dunk it in 99% isopropyl Alcohol swish it around and blow compressed air into.... Ahh I think the only openings on Galaxy 7 are the Sim card slot and the headphone jack. So you might want to remove the back cover to blow out the Alcohol. Youtube has a disassembly video but in short you need to heat the back to soften the glue then pry up a tiny corner of it with a razor blad or exacto just enough to get a playing card (No kidding) into the crack. Then use the playing card to cut around the edge to pop it off.
If its been days and you've tried turning it on (Bad idea) your phone is probably ruined.
Wet phones are the worst problem.
If you manage to get it going after the 99% Alcohol bath back everything up and assume its likely to fail.
*Note SPEED is critical. The longer its not cleaned with 99% the more damaged the phone will get. Drug stores sell mostly 70% and is not good. *In fact I think it screws the phone up worse. So be sure its real 99% nothing less.