A breakable odor control additive provides release of fragrance or odor masking scent when present in a litter formulation that is used by a cat or other animal within a litter box. The odor control additive comprises a plurality of fragrant-scented balls. Each of the balls has a central, compressible, porous, open-celled substrate, which is saturated with a fragrant scent. This central, fragrance-saturated substrate is coated with a barrier coating, which prevents evaporation of the fragrance and protects the substrate against deterioration by urine and other contaminants deposited on the litter. When cat or animal enters the litter box, a load is applied to the fragrant-scented balls. The barrier coating breaks, exposing the fragrant coated substrate. Fragrance evaporating from the substrate provides odor control and a pleasant scent.