I'm too lazy to look for an image, but I remember Duke Nukem 3D had toilets you can sorta use. Though it was so old it was basically just a picture on the wall you could walk up to and use to make the character talk. He would say something like: Ah...much better. I thought it was the funniest thing as a kid.
Also I always put a toilet in my house in Animal Crossing. Imaginatioooooon.
NNID: Zephyr25 / PSN: Zephyr--25 / Switch: SW-4450-3680-7334