From Old Fashioned Tips

Try taking it outside and setting it in the sun---or hang it if you can--be sure to expose both sides by turning it. You can also use 1 cup of hydrogen peroxide mixed with 5 cups water to wash it, THEN put it in the sun. Try this and see if it helps. If not, you could sprinkle baking soda on one side, then shake or vacuum it off. Turn it over and do the same to the other side.

OUR READERS' ADVICE

I noticed a member was asking about a work out mat that had a musty odor. Aquarium charcoal will help absorb musty odors, so will plain charcoal. I once had a freezer that had a musty odor, and we placed a container of charcoal in the freezer, and closed the door. A week later the odor was gone. She might like to try placing the mat in a large plastic container and putting some charcoal in the container with the mat. Leave the mat sealed up for a few days, and see if the charcoal helps. ~Charlotte

Regarding the karate mat which smells musty: first, rinse it very well. Then, make a solution of ammonia and water (for example, 1/2 C. ammonia to a large pail of water). Do this outdoors to allow the fumes to dispel. Scrub well with ammonia, then rinse well again. Hang on a line (or a deck railing, etc.) and allow to dry in the sun. Ammonia is powerful, so use judiciously. It is excellent for removing odors from many things. I use it in laundry, especially when washing men's work clothes and items that have begun to mold. As always, NEVER allow ammonia to come into contact with chlorine bleach; it can produce fatal fumes. I was present when someone did that accidentally, and I nearly collapsed. ~moonrani