When I was a kid one of my jobs was cutting the grass, well there was always piles of crap from next doors dog so I would get the shovel and fling it back where it belonged, on their driveway, walkway and sometimes their cars. One day my dad asked what I was doing, I told him and he just smiled and walked away. after a couple of times doing that, the dog stopped crapping in our yard, nothing was ever said!