Dog Obedience Collars

What will stop a barking German shepherd, has been and remains the obedience dog barks?
My dog is walked twice a day until warn out and is assigned the attention but he keeps barking when every time someone walks in front of my house. I heard about the necklaces and let me know if they work and what is best, I just want to use it while I'm at home because I still want to protect my home when I'm not here. Please help
The causes of problem barking can be: genetic predisposition (some breeds are prone to bark more often) inadequate confinement (a dog in a room locked, a locked drawer or chair dog without shelter from the elements) Lack of exercise (stored energy is released through the Bark – ruled in this case) Environmental sounds (other dogs, cars passing, thunder, ringing phone) Boredom (long periods without playmates or toys) Separation anxiety (a dog may bark for attention) shock collars and bark collars: These devices are recommended only after other control measures have failed and should only be used as a last resort when all other methods of behavior modification have been tried (in particular, when the dog's life is that question). Never use a bark collar on your dog if his barking is due to separation anxiety, fears or phobias, because punishment always makes fear and behavior anxiety. Teach your dog a "quiet" command. When it starts to bark at a passerby, allow two or three barks, then say "quiet" and interrupt his barking by shaking a can filled with pennies or jets of water into the mouth with a spray bottle or water gun. Have your dog neutered (or spayed if your dog is a female) to decrease territorial behavior. Natural Remedies Fortunately there are many natural ingredients to help reduce excessive barking and helping to solve the underlying causes of excessive barking in dogs. Herbal and homeopathic remedies can provide the solution! Herbs such as Hypericum perforatum laterifolia and Scutellaria dog can help treat anxiety and other nervous disorders, providing tonic benefits for the entire nervous system. Belladonna, and Nux vom Cantharis are homeopathic ingredients used to alleviate high levels of irritability, aggression and anxiety – all can contribute to problems with excessive barking and behavior. You can http://www.healthherbsandnutrition.com/pets/problempetsolution-behavioral-cats-dogs.htm details here
Dog Shock Collar Test