Answer to: water damage...now working, but dim displayYes, rice will work even after a while, even after days. Rice will pull the moisture out. Sometimes there is permanent damage (rice won't fix this). Sometimes there's rust or corrosion which would require cleaning. Sometimes though, the moisture just causes a short (an example is my friend's iPhone button wouldn't work... it had been weeks). If the moisture is removed, it may fix some of the problems. FYI: Silica packets also work.
Answer to: water damage...now working, but dim displayAfter a phone is submerged, first dry it off, then stick it in a bag of rice overnight, maybe even for a day or two. Rice pulls the moisture out of the internals. This is why they put rice in salt shakers, to absorb the moisture. You could use silica packets or purchase one of the specialty "emergency" bags, but rice works just as well.