And how many bags of dog muck do you see hanging from bushes when you go out for a walk? If the owners are going to make the effort to clean up their dogs mess and put it in a bag, why then throw it in to a bush where it will not decompose????? Maye once all the dog owners clean up the dog poo, the cat owners will have no excuse.
I would rather step in a dog turd then see them hanging like cheap Christmas decorations from the hedgerows.
Just my 2 cents to stir the pot a bit more
As to keep them out of your garden, water pistols are good, as are spices pepper, chili powder that sort of thing.