Sponges are an eco-friendly and reusable choice of cleaning products, but they can trap bacteria and actually spread it around on the other surfaces you're trying to get clean. Yuck. Instead of throwing your sponge away every time it starts to get funky, you can disinfect the sponge. Wet the sponge and wring it out, then microwave it for two minutes. The microwave kills most of the bacteria and extends the life of your sponge.