I am allergic to the powders you sprinkle on your carpet before vacuumming, but this tip I read in my ezine worked for me: Homemade Carpet Freshener

Freshening carpet is a breeze when you mix one teaspoon of cinnamon or other great smelling spice into 16 ounces of baking soda. Sprinkle on your carpet before sweeping. This carpet freshener does not cost a lot to make and has a wonderfully clean fragrance. You can adjust the amount of cinnamon if the fragrance proves to be overwhelming or is not strong enough.
Lisa B. in Beattyville, KY