Loosening of the collar happens with most adjustable collars that is why the Martingale collar is such a good one. It won't let the dogs heads out. It tightens and doesn't loosen up until the dog stops pulling. It also helps with walking as the dog learns to pull less. Jasmine my boyfriends 9 year old Golden used to pull like crazy but with the Martindale collar you can actually have an enjoyable walk. I only use the Martindale collar for walking, I actually have her regular collar and martindale collar on when we walk and can switch back and fourth when need.

What is also going to be important is that everyone in the household follow the same set of "rules" you are making. Like Alex sits before she gets her dinner. etc.

I'm glad I could be of help. Keep up the great work.
Gina