The sponge is dirtier than the dish.

Yeah, that's right. Scary, isn't it? All those bacteria that make your sponges smell so bad also can carry disease, and you wipe them right back onto the dish when you wash by hand. Solution? Well, there are several.

One possibility is to replace sponges with dishrags, and wash them regularly in the laundry. That works well if you can handle that level of change in your life, and if you wash in hot enough water to kill germs.

If you don't use hot water in the wash (which is bad for most of your clothes), you might consider switching from cellulose sponges to the foamy kind, the ones that resemble cheap chalkboard erasers. They don't hold nearly so much bacteria, and are much easier to wring out.

Step two is to throw them into the dishwasher regularly. Even if you wash clothes on cold, hot water is still better for your your plates. And your sponges.

They won't last forever, but you will get a bit more use out of them than if you never wash them.