MOM Tip: Do your dish clothes smell sour? Then try this home remedy:
Pour one tbsp. of non-bleach liquid dish soap and three cups of white vinegar into a clean sink or bucket.
Soak the sour-smelling dishcloth in the liquids for about an hour.
Rinse the dishcloth thoroughly.
Wring the excess liquid from the dishcloth. The cloth doesn’t need to be completely dry, as long as it’s no longer dripping wet.
Place the dishcloth in your washing machine. Wash and dry the dishcloth as normal.
This tip from eHow Home.