One thing cats and children have in common is their desire to sully a freshly cleaned bathroom/ litterbox.
The first thing a cat will do upon seeing you clean its litterbox? Climb in and defecate odiferously, relishing the fresh litter between its toes.
So with bathrooms. The first things Winton, for instance, will do when presented with a clean bathroom? Defecate odiferously, attempt to wipe himself (so besmearing the toilet rim) and hop off the toilet, depositing a small daub of poo on the bathroom floor.
On this one issue, I prefer the attitude of dogs by far: a dog will choose a spot far from home, ideally, in which other dogs have already pooped. A dog prefers to poo in an area that isn't clean, that hasn't been freshly sanitized. A dog likes to leave its poo on a busy message board of other dogs's poo-odors: a clean place is no fun. Would that the children would choose to poo far from home as well.