Sweet PDZ Horse Stall Refresher Granules capture, neutralize, and eliminate harmful levels of ammonia and odors. Sweet PDZ is made from an all-natural, non-hazardous, and non-toxic mineral commonly knows as zeolite. Sweet PDZ Granules absorb moisture and neutralize ammonia and odors while providing fresh and safe air for your horse in its stall. One bag of Sweet PDZ Granules lasts approximately 3-6 weeks in a stall. Granules.