Mason jar air freshener - fill a small mason jar about 1/4 full with baking soda, and add 6-8 drops of your favorite essential oil. Punch holes in the lid, and place in any spot that could use some freshening. Every once in a while, give the jar a gentle shake to boost it's air freshening power. Doing this in all the bathrooms and near litter boxes.
CBS did a special which stated "a straight 5% solution of vinegar kills 99 percent of bacteria, 82 percent of mold, and 80 percent of viruses". That's really amazing! Apparently salmonella only needs a 1% solution to be killed. When vinegar is combined with table salt or hydrogen peroxide, it can inhibit the growth of certain strains of e.coli. NOTE: Do NOT mix with bleach! Toxic fumes can result. (She gives two recipes for diy vinegar cleaners.)