Yes, baking soda can help to absorb the moisture in a closet. Baking soda has a natural moisture-absorbing ability, which makes it useful in eliminating excess humidity that can contribute to mold creation. Place an open jar or a cloth pouch filled with baking soda in the closet. Baking soda can help eliminate moisture and odors. To ensure the baking soda continues to be effective, refill it or replace baking soda containers on a regular basis. However, while baking soda can help manage moisture, it may not be as effective as a dehumidifier for treating the underlying cause of moisture.