How Febreze WorksThe cyclodextrin molecule sort of resembles a donut. When you spray Febreze, the water in the product partially dissolves the odor, allowing it to form a complex inside the 'hole' of the cyclodextrin donut shape. The stink molecule is still there, but it can't bind to your odor receptors, so you can't smell it. Depending on the type of Febreze you're using, the odor might simply be deactivated or it might be replaced with something nice-smelling, like a fruity or floral fragrance. As Febreze dries, more and more of the odor molecules bind to the cyclodextrin, lowering the concentration of the molecules in air and eliminating the odor. If water is added once again, the odor molecules are released, allowing them to be washed away and truly removed.
Some sources state that Febreze also contains zinc chloride, which would help to neutralize sulfur-containing odors (e.g., onions, rotten eggs) and might dull nasal receptor sensitivity to smell, but this compound is not listed in the ingredients (at least in the spray-on products).