There are plenty of people who want to do better, but need some accountability. Used for that purpose it could definitely be helpful. If the kid is defiant, and the parent says one bad drug test and you're off to get yelled at in some facility for troubled youth, then I don't think that's the battle a parent should fight.

None of my kids have had substance problems, but I had one kid go off the deep end with grades, and we fought some major (losing) battles. I finally gave up the fight, the kid squeaked by with graduation, and is gradually turning things around as a young adult. I was just at the point of wrecking communication with that child when I pulled back, and am glad I did.

Some things are easier to mature away from than others, which is why I ask if we're talking pot or if we're talking meth.