That sponge smells disgusting, but why spend money and toss it in a landfill when you can easily remedy the problem. Plop your stinky sponges in a solution of hot water and dishwashing detergent, then dry. If that doesn't work, mix a quart of water with three tablespoons of bleach: soak for five minutes. Color code your sponges and toss after two to eight weeks.