I bought new cellulose sponges today and as I was reading the packaging I learned something...to increase the life of your sponges to do not wringe them dry, just squeeze dry. You can freshen your sponge by running it through the dishwasher once and you can sanitize it by putting it in boiling water. I also cut my sponges in half to make them last longer. The package of four claims it will outlast "rolls" of paper towels.