I have an electronic litter box. Is that what you are talking about?
My electronic litter box automatically pushes all the cat waste to a side of the litter box which is covered, so it cleans and traps the smells of the litter box.
I just took the cover off of my electronic litter box because my cats were leery of the cover and avoided the litter box when it was covered. Now they are happy with the new electronic litter box and use it regularly. It definitely keeps the box cleaner and it smells a lot less.
https://drive.google.com/file/d/0B0BdTN ... sp=sharing