That is so totally false. Dogs LOVE to smell and be dirty, and cats love to be clean and will always wash themselves. They spend about a third of their day cleaning themselves. A litter box is supposed to be scooped ...preferably several times a day...because most cats won't use a dirty litter box. So, if yours is gross, your cat thinks so too but has no option. It's your job to clean it and keep it clean. Then of course, dogs love to eat poop, so you can just have your dog keep the litter box clean.
My dogs don’t smell, aren’t dirty and do not eat feces.
As I stated in my post, which you did not seem to comprehend, I no longer have cats. Was nice of you to infer that the cat box was filthy when we had them though. You’re a sweetie.