Things You'll Need
1 cup rubbing alcohol
Space heater, optional
When mold spores are introduced to damp conditions, mildew can form. Most traditional mildew removal techniques involve washing or rinsing with bleach but using bleach on wool can damage and yellow the fibers. Fortunately, there are other bleach-free solutions to kill mildew.
Bring the rug outdoors. Sweep the mildewed rug gently to dislodge loose mold spores. Brush over the mildewed area only. Avoid passing the broom over clean sections of carpet and possibly spreading the spores.
Vacuum the mildewed portions and the area immediately surrounding the mildew. Throw away the used vacuum bag. If you have a canister-style vacuum, clean it outside afterward to avoid spreading more mildew spores.
Mix 1 cup of water with 1 cup of rubbing alcohol. Moisten a cloth with the solution, wringing it out to leave it damp but not saturated. Scrub the mildew vigorously, dipping the cloth in the alcohol solution as needed.
Wash the rug with a carpet shampooer if mildew is still visible after cleaning the wool rug with alcohol. Rent a carpet shampooer from a rental business if you don't own one.
Hang the rug up to dry or lay it flat on a hard surface outdoors. Allow the sun to dry all moisture in the rug. Dry the rug with a space heater if it is not possible to dry it outdoors.
Avoid cleaning wool with bleach. While bleach is commonly used to remove mildew, it damages wool.