Zeolite to the rescue!
Zeolite is a porous volcanic mineral that absorb moisture and gas at about 65% of its own weight. We bought a combo bag set (one large bag and smaller one for the closet) from the Container Store a few months ago, and it’s noticeably reduced litter box odour at least 75%, and still working its magic. And the best thing is zeolite’s effectiveness can be renewed by simply exposing it to sunlight for a few hours every six months. Great for your own bathroom, closet, and fridge too.
We find it ironic that the earth’s past eruption helps control our cats’ present-day eruptions. Yay nature!