Wait 48 hours minimum before putting the battery back in.
No need.
Forget the rice; just take out the battery bang out as much as you can. Let it sit for about 3 -4 hours the take a blow dryer and dry it. Don't get too close as to not melt anything inside.
Let it sit till the next morning all will be fine.
If the battery was in it for more then 3 min (sometimes even less) say bye bye phone...
I work in the cell phone industry and this is my experience for many many cases.