5 cats, 5 litter boxes, extra large size, all in the same basement room created specially for that purpose....I scoop the boxes at least 4 times a day, usually more.
I use dust free scoopable litter. I used to use regular clay and changed the entire boxes every week, but that was before I discovered scoopable litter. I love it!
As for brand, right now I find Costco brand economical and efficient, however, I have heard from reliable sources (insert Chico here
) that the formula has been changed so I will have to find a new brand.