No, you don't understand. He pisses in the litterbox. He KNOWS what it's for...he just won't shit in it or in anything with sand. He prefers things like tile floors, the bathtub, the bidet, the FUCKING SINK...argh.
In fact, he just shit IN FRONT of the litterbox.
We thought, "Hey, maybe he's shy! Let's get him one of those covered litterboxes so he has a little privacy."
Nope.
And you're right, you can spank him and scold him but he still does it anyway. I gave up spanking him and just held his nose in it for about 2 minutes. Still doesn't work. You have no idea how hard-headed he is.