What is the best way to maintain the litter box? I have two cats and it seems like scooping is too messy and the scooper gets all gross. I've tried those bags that you pull up and the used litter is supposed to stay in the bag, while the unused litter falls back through the holes. Using that, some used litter seems to always stay and that is messy too. One of my cat's doesn't cover up their poop. Now I have resorted to throwing out all the litter each time I clean it. I also have stopped using plastic (or whatever material they are) litter boxes because the kitties always seem to rip through the liner and poop gets on the bottom of the box. Also, using liners...they always seem to get them off of the box and try to cover their poop with it...making that gross too. Now I use card board box tops. Any suggestions of an easier way to go about doing this?