We knew the people who previously live in our house had 3 large cats, but we were totally unprepared by the amount of friends they had. Cats poo everywhere, and certainly not buried, on the decorative stones in the front garden, and on the gravel. Luckily my greyhound made sure they were not welcome in the back garden!! I too tried all the remedies I googled on the lap top, but then I put lines of canes on the gravel interspersed with wooden skewers. After a while the cats moved on elsewhere, but the canes and skewers remain. At least when my dog has a poo I clear it up. Cats just go wherever they like, and putting your hands in their excrement (even with gloves on) is really disgusting!!