The dirtiest room is the kitchen, the dirtiest spot is the sink and the worst culprits are the sponge or dish towel. Bacteria colonies with a total population exceeding 50 million can live on a single dirty sponge. And that’s what you use to wipe down countertops, forks and drinking glasses. Eeeew..
The best bet is to soak the sponge for about a minute in a solution of bleach and water (approximately 1 ounce of bleach to a quart of water will do) after each use. Another option is to boil the sponge for three minutes. Nuking a sponge is not as effective, since microwaves have dead spots, and dishwashers won’t necessarily reach 155 degrees Fahrenheit, the temperature needed to kill germs.