I purchased Petsmart’s Sifting Litter Box with Frame for $19.99. Since I have 6 cats, I bought 2 of these and have 2 standard litter boxes for comparison.
I used the frame, which encloses the box and elevates it a little to avoid spread of litter, for the first week and then decided it was too much of a pain to use. The cats would still spread litter – even with the frame – since they were more likely to jump out of the box then step.
I had to remove the frame to clean out the litter box twice a day, but I was uneasy about it since the frame occasionally had fecese on or near it. When unlocking the frame, litter would fall all around the box since it become lodged in the inside lip.
However, the sifting part of the litter box works great. You pick up the plastic (again, you have to be OK with touching so close to their messes) and you sift side to side. The litter falls out the bottom and you are left with the mess on top which can be scooped or dumped into the trash.
I have used various types of litter and found the clumping kind to be the best litter for this box. When I used a litter that didn’t clump, the urine would just seep through the grate and I would have to scoop what fell through the sift anyways. With the clumping litter, all mess stays on top of the grate leaving the clean litter to fall.
The only problem I have is if I let the litter go a day or so without cleaning then the clumping areas of urine can clump around the grate, forcing me to scrape and bang it to get the clumps out of the holes in the grates.
This particular model came with 2 boxes, 1 sifter and 1 frame. In normal conditions, you remove the frame and sift the litter. Dispose of the waste and set aside it aside. You then take the clean box, place it on top, place in the filter and sifter, then fill with litter. It is a lot easier seeing it than explaining it!
I would recommend a sifting box for someone willing to clean it out regularly with multiple cats or clean perhaps every other day for a single cat. It can be a bit more work but I like how the litter is moved every day and not just sitting there on the bottom until the next change-out.
You can get the Sifting Litter Box for the best price here: http://amzn.to/afBs0t.