I think it's a great thing to teach your dogs not to eat anything without "permission"
I am still working on this with Jaxon. He's really good at dropping whatever he picks up as long as I give him the command, but if he can sneak a floor snack behind my back he will, lol!
He also has this habit of taking a mouthful of food out of his dish and dropping it on the floor to eat it...what's that about???