I am a 16 year plus karate mom.
Yes it is a good idea. Because if you have an instructor who's on his toes, he'll make disruptive kids do positive disciplinary push-ups. But I will say this too.
1. It will take you reinforcing it at home too. I suggest stay in the class on the sidelines and observe the blocks, punches, kicks, etc. so that you can help him practice at home. Practice practice practice. I've seen too many kids in class that don't put effort in class or at home and the parent knows it. I've seen parents who come to class with little siblings who run around and are very disruptive. That's a bad thing. I've seen parents who drop their child off, don't know a thing what's going on. The more interaction and involvement the better. Some parents think that this is a glorified babysit and if the child is unruly at home, the instructor will whip them into shape. NO. It takes more than that. It takes reinforcement, because
2. Even the instructor has a breaking point. I know a family that the mom wore the pants, dad was a wimp, and the kids were put in karate. They didn't practice at home, they were cheeky and talked back both at home and in karate. One evening the older child was the absolute most disrespective I've ever heard, the instructor calmly responded that he agreed with the student that he doesn't have to do what's expected; especially in the class and he proceeded to tell the student that he would no longer be training in that class or in the instructor's club PERIOD.
A very spoiled brother and sister team. Both very disrespectful.
So if you're in the South Lyon, Milford, Highland, Ypsi, Northville/Novi area, let me know. I have 3 sons, all of them are second degree black belts. I can hook you up with this instructor. I recommend him. He's good with kids, firm, makes it fun to learn and train, and he gets the job done. It's competitive, they offer tournaments (their national tournament is July 11/12 at the RenCen), and other events.
Let me know. And best of luck.