Soaking a sponge in pure lemon juice for about a minute not only impedes the growth of harmful bacteria such as E. coli but also leaves it smelling fresh and citrusy.
Put your sponge in a pot of boiling water, ensuring that it is completely submerged. Boil it for five to seven minutes before removing it with a pair of tongs.
According to the USDA, microwaving sponges can kill up to 99.99999% of bacteria, and the Environmental Protection Agency even recommends microwaving sponges daily.
Ensure your sponge is microwave-safe, and avoid this method for abrasive sponges that may have bits of metal. Then, wet it and microwave it at 100% power for at least one minute.
Any sponge can go into the dishwasher. Simply rinse off any debris before adding it to the dishwasher along with your dirty dishes and wash on the hottest, longest setting.