Cranky Benches Roll Off Water After It Rains

Anybody who likes to go to the park after a good rainstorm knows the butt-soaking hazard of still-wet bench. Some design gurus in Korea decided to solve the system with a simple crank: give it a couple of turns, and the soggy slats at the top roll to the bottom while the dry slats below revolve back on top. This "rolling bench" innovation solves the problem of water, which will definitely evaporate or just drip off, but it doesn't solve the problem of other park-bench friendly substances, say the blue puke of a kid who's gorged himself on cotton candy. What do you got for that, O Mighty Design Gods? [Yanko]