Those perfect books inoculate against the coprophagia forever. Once inoculated you become immune and when you see a hysterical coprophag you just frown in disgust and turn away. It is like having those special glasses I saw in one movie with Roddie Piper: you put them on and see all the bad aliens around you.
To be immune is no fun, but it is healthy because it means maturity. Good luck to all of us; we are adult dogs from now on.