I had a dog who did this a few years back too, (the eating poop thing), not the grass thing, but what I found really worked was filling a spray bottle with white vinegar, and as soon as he goes, spray the poop with the vinegar generously, and when he tastes it, he will be detered from eating it. I tried all the pet store "fixes" for this problem and to be honest none of them work. But in my experience, try this, it might help.