I don't know whether this will help, but this is my experience with a Litter Locker used for one cat for the past 4 -5 years. I use a very fine clumping litter, and scoop the litter box twice a day. I put the clumps/feces in the Litter Locker, and give the wheel on the side a half-turn every day, meaning after every other scoop. I use scissors, rather than the "knife" in the lid, to cut the foil, and dispose of the "packaged" waste every week. One foil refill lasts about two months that way, and there's no problem with odor. However: Jamie is not a strictly indoor cat, because I take him for a walk on a leash and harness every day, and he does quite a bit of marking outdoors. He never defecates outdoors, though. I'd estimate that a refill would last about 5 or 6 weeks if he exclusively urinated in his litter box.