Tea Tree Treaure
Nothing natural works for mold and mildew as well as this spray.
I’ve used it successfully on a moldy ceiling from a leaking roof, on a musty bureau, a musty rug, and a moldy shower curtain.
Tea tree oil is expensive, but a little goes a very long way.
Note that the smell of tea tree oil is very strong, but it will dissipate in a few days.
2 teaspoons tea tree oil
2 cups water

Combine in a spray bottle, shake to blend, and spray on problem areas.
Do not rinse.

Makes 2 cups
Preparation Time: Under a minute
Shelf Life: Indefinite
Storage: Leave in the spray bottle
Straight Vinegar Spray

Straight vinegar reportedly kills 82 percent of mold.
Pour some white distilled vinegar straight into a spray bottle, spray on the moldy area, and let set without rinsing if you can put up with the smell. It will dissipate in a few hours.
You can also use these products alone to remove stains:

Hydrogen Peroxide
Fels Naptha
Castile Soap