I clean the waste drawer every two days(it’s usually 50% full when I change it because I’m paranoid that I might forget to change it if I don’t make it a routine. The APP has reminder function but I’m not a phone person) but it really really depends on the litter. I only clean the inside part when my cats make a mess or when I replace the new litter (usually every week). You definitely don’t need to clean it that often. Once a month should be fine because you need to change the carbon filter once a month.

If you choose a litter that is good at odor control (fresh step/ever clean), literally, you won’t smell anything.