Nylon netting, which is very inexpensive in fabric stores, makes an excellent scrubber for kitchen and bathroom sinks and tubs. Cut a strip 2 yards long and six inches wide and gather in the middle, using a large needle and strong thread. Pull the gathers tight, wrap the thread around the center of the "rose" and tie off tightly.
Or, just cut a piece eighteen inches square and use to scrub surfaces.

Food and other yucky particles can be easily rinsed out, and it's so inexpensive that it can be thrown out with a clear conscience when it wears out.

(Thanks to Tallysmom of the About Cats Forum for this tip!)