I scoop 2 or 3 times a day (depending on who does what in which box ) and add litter on a weekly basis. They use the boxes so much that my weekly adding of litter is all I need. If I didn't add littler every week, it would be completely empty after 2 weeks. I think I might scrub and clean it 3 or 4 times a year. Maybe. That too depends on which box: the box in the closet seems to need it more often than any of the others (don't know why, but it does). It sounds gross, but I promise my boxes are clean. My rescue friends who have seen my boxes are impressed with how neat and clean they are. They have to be since Allen gets cranky if they aren't clean