I have two rescue cats, the sweet, shy female came in about two years after the first one, a dominate male, arrived. After a couple of weeks they get along like sister and brother, which means they fight sometimes. And the female starts a lot of it,
even though she was declawed when she got here.
The littler box fight goes on all the time. He won't let her even stick her head in HIS, but he feels free to use hers, which makes her mad and I think it smells worse from her actions. She wants hers cleaned twice a day but will reluctantly agree to once a day, but if forgotten, she will use a throw rug in the bathroom just to let me know. She will even squat down while I'm watching, while I, myself, am squatting on my own throne.
Cats are strong minded critters, but the love they give is well worth the work. I wouldn't take anything for my fur kids.