My girl was a dirt, rock, sand, brick, and grass eater! She is now a little over a year and has given up all but the grass. The vet said a lot of pups eat dirt too and they'll just grow out of it. The sod my girl still goes crazy for but we just leave it covered until we are ready to lay it out.. Did you try burying the poop? Maybe give him massive distractions like cow hooves, pig's ears (you have to monitor those), knuckle bones and stuff like that. make those his "outside" treats so he dosnt tire of them inside and so when he does go out he'll be hunting those down instead. My back yard is littered with cow hooves but at least the grass is nice now!