Related Clues:

• Do some housework
• Dirt
• Composition of some clouds
• Run a cloth over
• Sneeze inducer
• Do some housecleaning
• Collection in the attic
• Common allergen
• Attic buildup
• It looks bad on the surface
• Sign of disuse
• Sign of poor housekeeping
• It settles indoors
• Tidy up, in a way
• Motes