Clothes begin to smell musty when they are in an area of high humidity because a bacterium that is present on the clothing starts to grow into an invisible but malodorous kind of mould. This mould might only be on the clothing or it could be in the closet in which they are stored, creating a more general stench. Either way, there are ways to treat the odour without damaging the clothes or permanently altering the closet.
Put clothing in a tote (or the bathtub) with enough cold water to cover the item.
Add a half cup of vinegar to the water and stir.
Allow the garment to soak overnight.
Wash the garment according to procedures appropriate for the clothing's material.
Hang the garment in the sun to dry. If the garment cannot withstand direct sunlight, you can instead place the clothing in the dryer with a washcloth soaked in vinegar, and run the dryer until the garment is dry.
Place the charcoal briquettes in multiple places in the closet where it cannot touch clothing, such as on the floor, an upper shelf or in a pillow case hung over a hanger. The briquettes will absorb the musty odour and any dampness in the air.
Remove the briquettes after they are saturated with the musty odour, and replace them with new briquettes.
Repeat this procedure until the musty odour is gone.
If clothing is dry clean only, run very hot water into the bathtub and add vinegar. Hang your clothing on hangers above the tub so that they are in the steam created by the hot water. You may have to do this multiple times to fully remove the musty smell. If vinegar does not remove the musty odour, try adding chemical odour-removing agents to washing powder when washing the musty-smelling item in a washing machine. These products can be found at sporting goods stores and online.
Using certain sprays intended to get rid of a musty odour in clothes really only masks the odour because they don't kill the odour-causing agents in the material. Bleach will get rid of the musty smell but can damage or fade the clothing.