I know there are enzyme cleaners - but I'm still doubtful that they eliminate ALL scents? We're talking DOGS here - the ones who can find drugs concealed in some amazing ways; the ones who can detect skin cancer; the ones who can detect blood sugar levels in diabetics - and here's a new one: the ones who can determine the difference between human E-coli and animal E-coli (is it the beer and Doritos that sets us apart?? LOL!). So I suspect they *know* - it's just convincing them to ignore the obvious, I'm afraid.
Ben is going through a stubborn streak right now - whatever I want him to do - he wants to do the opposite. sigh... I DID find his weakness: liver. He'll sell his soul for freeze-dried liver LOL!!! So I have it stashed everywhere (little sandwich bags of liver - sure hope my car doesn't ever get searched; they'll think it's the new illicit drug?") - in case I need to reward outstanding behavior :-)