Make them sign a form that says:
I will hereafter produce no defects.
_X___________________________
or a sign that says, "increase productivity!" (man running up stairs)
Not being facetious, I really think Deming's examples from Crisis are funny. I also think that a good quality slogan does go a way into increasing a person's pride of workmanship and pride being on the job. Usually. Or sometimes.
maybe.