#6: Elbow Grease.
Ultimately, the best way to deal with smelly or chemical-laden indoor air is to go straight to the source. It's easier to eliminate an odor's cause than to try to cover it up with coffee grinds or cat litter. And indoor air pollutants that collect in dust can be trapped by a good vacuum and weekly dusting with a damp cloth. To prevent further polluting your indoor air, make your own green cleaning kit with white vinegar, lemon juice, baking soda, and borax, all of which are also natural odor removers. For cleaning recipes, see How to Make Green Cleaning Recipes That Really Work.