I've tried dog poo for scent/territory stuff. I've tried the dog herself.
Unlikely to work. Dog-occupied territory tends to be a demilitarised zone in cat terms, which makes it an ideal place to poo (as long as you can avoid the dog) without risk of offending other cats. They don't care about offending dogs. Dogs are uncivilised creatures that will shit anywhere, after all.
Hence the canonical solution of getting a cat. Except that cats will go in their own territory if there's a particularly attractive patch, so it doesn't really help. I suppose the same can be said for owning a nasty bastard cockerel - it may keep the cats away but now you've got the cockerel to deal with.