The idea seems to be good, specially how my house is set up I'm unable to see my dog at the door so the noise will allow me to take him out. I just got these yesterday and started training my little guy he is 12 weeks old, what I do is take him to the door let him see the bells I then say a command "Potty" push the bells with my finger and say GOOD BOY! then I'll take him out. He actually started pushing them with his nose that night I would just point at the bells with my finger, then I will still say GOOD BOY!! potty.
One thing I have noticed that some people do is give a treat when they hit the bells this is a bad idea the dog will put two and two together and just ring the bells for the treat and not want to go outside just stick with what the book says that it comes with. If everyone in the house sticks with the same thing there should be no issue training your dog overtime.
I gave 4 stars for the simple reason that the quality is just not there for me the "Ribbon" or whatever it's connected to is not to thick the bells and other things attached to it very good.
Overall this idea seems great hopefully my litttle Dexter will pick it up quick and stop these 1-2 potty breaks in the house.