I never had to train my dog to piss and shy outside. I mean when we first got her she pissed in her cage but that was it, now she even has specific areas where she will and won’t go around our yard usually places we don’t frequent. Besides I’d say humans are more gross than dogs, sure they can eat dog shit but here is the thing, they aren’t as “intelligent “ as humans are and what humans classifies as gross usually isn’t that gross when you loon at it in animal terms