Rice does work, which is why people sometimes put it in their salt holders to stop it lumping from moisture in the air.
The problem with pools is, they are either chlorinated or salt-water treated, both of which sooner or later cause corrossion. I remember someone telling me once, if you drop a phone/electronic device in a pool with chlorine or salt, you should rinse it under the tap to get the chemicals out then dry it. otherwise you dry the water and the chems stay behind and start eating away at stuff.
I wouldnt try it now though as that phone is probably pretty much dry. Hope it starts working again. Its why I dont like using/holding other people's phones.