First, remove loose mold from outer coverings of upholstered articles, mattresses, rugs, and carpets by brushing with a broom. Do this outdoors, if possible, to prevent scattering mildew spores in the house. Wash broom before re-using.
Run a vacuum cleaner attachment over the surface of the article to draw out more of the mold. Remember that the mold spores are being drawn into the bag of the vacuum cleaner. If the vacuum has a disposable bag, remove and dispose of it immediately. If not, empty the bag carefully (preferably outdoors) to avoid scattering mold spores in the house.
Do everything conveniently possible to dry the article--use an electric heater and a fan to carry away moist air. Sun and air the article to stop mold growth.
If mildew remains on upholstered articles or mattresses, sponge lightly with thick suds of soap or detergent and wipe with a clean damp cloth. In doing this, get as little water on the fabric as possible so the filling does not get wet.
Another way to remove mildew on upholstered furniture is to wipe it with a cloth moistened with diluted alcohol (1 cup denatured or rubbing alcohol to 1 cup water). Dry the article thoroughly.
Sponge mildewed rugs and carpets with thick suds or a rug shampoo. Then remove the suds by wiping with a cloth dampened with clear water. Dry in the sun if possible.
Use a low-pressure spray containing a fungicide to get rid of mildew. Respray frequently, especially in localities where mildew is a major problem.
If molds have grown into the inner part of an article, send it to a reliable disinfecting and fumigating service. Such services are often listed under "Exterminating and Fumigating" or "Pest Control" services in the yellow pages of the telephone directory.
This article was written by Anne Field, Extension Specialist, Emeritus, with reference from the USDA bulletin, Mildew.
Source: MSU Extension