We call our Aussie the "Turdinator"...Yep...she went through a time where she ate poo. I have taught her the command "Leave it" and she'll walk away from it. But that particular breed listens well. You'll have to let me know how the stuff works for you...I heard the stuff purchased at the pet stores doesn't always work. [I hadn't heard you could get anything from the vet] Thus I taught my pup to "leave it" and she'll turn and walk away from it.
Though...it really disturbed my husband...so for Christmas he got the book "Why dogs eat Poop" from...Ahsoka aka turdinator. They really don't know why dogs eat poop...but say that they are not the only animal species that do so. But it's a cute book with tons of information on all sorts of animals and insects.