Hi
Although it's possible that you might have permanently short circuited something, modern electrical devices are remarkably resistant to water damage, so don't give up yet. What you are waiting for is the total evaporation of ALL the liquid in the case, but this can actually takes weeks not days. Some things that slow the process down:
Being in a tiny space means that the surrounding environment is already saturated with vapour so evaporation slows to a crawl.
Having a very small surface area (it's probably just droplets lodged somewhere) slows evaporation to a virtual halt as well
Other substances dissolved in the water (ie soap in bath water) also slow down evaporation
I'd recommend putting the phone somewhere warm and dry, with circulating air, and leaving it there for at least another week. Carry on using silica gel or rice because that helps. You've got nothing to lose.
Ps Just thinking about you battery issue: the li-ion batteries are certainly not designed to get wet, but they are designed to withstand a certain amount of humidity and moisture (people put iPhones in sweaty pockets and go jogging with them etc). If water had short circuited the actual battery itself then I think you would have smelled smoke! I think it's more likely that you have battery terminal contacts which are still affected by water in some way, and which might be dried out.
Jon.
