During teething time provide things for him to chew on. For example, soak old wash rags in water, ring them out, and put them in the freezer. Whenever he has a need to chew on you or the furniture, give him one of these wash rags to work over. Provide a box filled with chew toys such as nylon bones or hard rubber balls.
Also remember that your dog learns trough pleasant or unpleasant experiences .
so the use of repellents will help with very strong headed dogs , and at the same time , i use the opportunity to start them in the" leave it"command or anti-food poisoning training .