I just have litter boxes. Many litter boxes.
I once tried to eliminate litter boxes because the little darlings went outside. Ha! They peed on plastic, in plants, on anything on the floor. And they will pee/poop in the garden, regardless. Next to the tomatoes. Lovely.
By the way, I'm redoubling my efforts to find a home for miss thing upstairs. She slept on my head last night. On my head.