Actually there are better options than rice, which did the worst job in one experiment.
Test 2: Is rice king?
We wanted to see if rice is really all it’s cracked up to be. We tested six common household materials to see which could absorb the most water from a wet sponge in 24 hours:
Classic rolled oatmeal
Silica gel (crystal kitty litter)
Rice is most definitely not king
Dry, uncooked conventional rice was the worst of the seven options we tested. It absorbed the least water in 24 hours, losing out to silica gel, cat litter, couscous, instant oatmeal, classic oatmeal and instant rice.
More importantly, the sponge that we left in open air performed far better than any of the drying agents. It’s possible that the absorbent materials could have matched open air if we’d used a lot more. But it seems that leaving your phone on a shelf may be the best option.