Why not add granular carbon to the litter? I have never tried this but apparently cats are not offended by the charcoal mentioned above.
If you want your cat to be indoors and also do not want to make your tongues and noses sour with bad odor, an active charcoal buried deep within the litter box is your only solution to drain the air off the stinky smell. You may interested to read guideline
Saturday afternoon, members of our happy hour group mentioned putting out pans of cat litter, charcoal, silica gel, and/or other chemical concoctions to "absorb moisture" during the hot, humid summer months. I mentioned that I didn't believe these actions would work because any moisture that would be absorbed had nowhere to go but back into the very air from which it had been extracted -- unless someone was there to empty or replace them.
Ever Clean EverFresh Cat Litter with Activated Charcoal
Ever Clean EverFresh Cat Litter with Activated Charcoal | Petco
Some covered cat litter boxes are fitted with charcoal air filters. The filters help to reduce the odor for humans. They may even help to reduce the odor inside the box for the cats.Just clip our odor eliminator on to your cat litter box or even outside small carrying cages to eliminate odors safely and effectively and without chemicals, gels, powders or sprays. Built in clip securely fastens to most litter boxes and cages. Don’t settle for litter that claims to control odors. Eliminate them with Innofresh® Pet activated charcoal odor absorbers. utilizes our patented activated charcoal carbon technology to eliminate kitty litter odor and is completely fragrance free. No worry about irritating or harmful fragrances for your pets or yourself. Fragrances just cover up odors while traps and eliminates those lingering odors from your . Our activated charcoal carbon odor absorbers work effectively against tough litter box odors, as well as in areas where cats are kept.Watch the labels on these litters. Recently, I noticed the fresh step litter now offered Febreeze in the litter, not charcoal. The label looked very similar and one client noted her cat started going out of the box. This cat was managing well with his bladder inflammation, so it was perplexing until the client noticed that Febreeze was added not charcoal! Read the label to be sure it says only charcoal as the additive.Cats are not only selective about the where, they are also selective about what they eliminate on. This is called surface preference. While there are many types and brands of litter, most are designed to appeal to the humans, not the cats. The deodorizers and pellet type can be offensive to many cats. In a study by Dr. Jaqueline Nielson, DVM, DACVB, in 2009 (), scoopable litter with activated charcoal was preferred over litter with baking soda or citrus scents.Although each piece is small, the surface area of activated charcoal is larger than it appears thanks to multiple pores. These pores trap odors as they pass through the surface area of the charcoal. Because of the large surface area they create, they can trap a large amount of odors. This makes activated charcoal useful for trapping odors that emanate from a cat's litter box. To work, however, the charcoal must be placed near the box.