Baking soda, so inexpensive and so versatile, is one of those products no homeowner should be without—and no cat owner. Soda absorbs and neutralizes the chemicals present in cat urine, so you can’t go wrong by sprinkling a thin layer of soda in the litter box, then pouring the litter on top of it.
Arm & Hammer, Tidy Cat and several other companies now sell boxes of “cat box deodorizers,” which are basically made of baking soda and some chemicals. Any of these work fine at keeping odors down. If you choose to use regular baking soda, keep in mind that you can buy it in large boxes, not just the small “kitchen size.”