Review on Arm & Hammer for Pets Cat Litter Deodorizer: 20oz (Pack of 4) with Activated Baking Soda - Ultimate Odor Control for Your Feline Friends by Brian Wright

Wow, this thing packs a devastating blow to the nasal passage! Oooooh! But he does his job. I have 2 trays and 99% of the time we forget they are there. It works out. I just put a little on the bottom of the box before putting the filler in (hand and hammer, slide) and then sprinkle a little on top to mix it up randomly. Then when we scoop poop/piss I add some more. Works perfectly!