Whether you've chosen to use lemon-water or plain water, the remaining steps are the same. Simply place your sponge (either in a bowl of lemon-water or resting on a paper towel) inside your microwave and close the door. Set your microwave to its highest setting. Then set your timer for 1 minute, and press start. Depending on your specific machine, you may want to microwave your sponge for up to 2 minutes. When your sponge comes out of the microwave, both the sponge and the liquid inside of it will be very hot. Allow the sponge to cool for at least five minutes before handling it. After the sponge has cooled, simply wring it out and it is ready to use. There is no need to rinse it. Repeat this method approximately once a month, or any time you feel your sponge needs disinfecting.
Place the sponge in the microwave. Microwave on high for 1 minute. Let the sponge cool before using. Use your sponge.