<--------------- Read my tag.
Sorry I just couldn't resest. I have a lot of fun with that tag.
All in good time. Is your issue with your DN using them, or his mother not potty training him? Have you asked her opinon in it? As a mother I learned that potty training actually wasn't about me at all, but about the child. I needed to let go of my trying to control it and leave it up to her. Only then was she able to get it.

As a mother I could do "everything right" and if she still isn't ready, that doesn't mater. The right thing to do was give her the "info and encouragment" she needed, and leave the rest to her.