The litter box:
A daily, dusty, dirty, never-ending job.
Twice a month, empty and wash litter box: 30 minutes
Then refill litter box; watch for dust: 4 minutes
Every day of month scoop clumps; dispose: 80 minutes
Twice a month, buy bags of litter: 10 minutes
Work: Scale of 1 low; 10 high. Litter Box: 10
Time: 124 minutes per month (25 hrs. per year)

Self-scooping litter box, on average 10 times a month
remove waste receptacle and dispose: 30 minutes
Add a new receptacle 10 times a month: 10 minutes
Clean rake, clean out crumbs: 12 minutes
Twice a month, buy jugs of clump litter: 10 minutes
Work: Scale of 1 low; 10 high. Self-Scoopers: 5
Time:  62 minutes per month

CatGenie:
Maintenance free in no time.
Every day, CatGenie completely cleans for you
and provides superior sanitation for your cats.
Just push a button or preset to run: 2 seconds
SaniSolution lasts 60 washings. It tells you when
it’s low and empty. Simply replace. 4 seconds
Washable Granules never need changing.
About once a week, add a bit to maintain correct
level indicated on the Bowl. 6 seconds
Once in 2 months order Supplies on line: 1 minute
Work: Scale of 1 low; 10 high. CatGenie: 1
Time: averages less than 2 minutes per month
 
All examples based on one cat. Times averaged.