Iphone says headphones are in when they are not?

I have an Iphone 4, ya I know its old, and today while walking to class we had a popup shower that was had some heavy rain. I got soaked and subsequently my phone did too. After the rain storm happened the phone was saying "Ringer (Headphones)" when I was trying to turn up the volume. No sound was coming out even while I was taking a phone call. I restarted it and it was still having the same problem. Since then I have turned it off and placed it into a large bag of white rice. Is this all I need to do to fix the problem? And if it is still saying the same thing after a night in the rice what should I do?

Then take it apart to get the rest of the moisture out. The moisture is playing stupid with circuits so it will throw errors. Unless all of that is out, then it will fry something or corrode and rust the rest. Best luck.