I've also come across a number of subs begging to be shit on, covered in it, and even in crapping in their mouth. Along with the scat they would also worship the penis/vagina as a sacred drinking fountain and blessing of a golden shower.
As a dom I personally enjoy a personal portapotty with all the sense of control and humiliation that comes with it. The best experience I've had was pissing on my slave covered in shit in our backyard where our neighbors could see and hear me verbally degrade him. The look of humiliation on his face was the perfect kodact moment lol