Just because you read it in a book a hundred years ago does not mean it is true. Just because you read it in a dog training book does not mean you should apply it to every dog. Just because you think it is a method that is working well, does not mean you have the slightest clue about dog training.
My mother, the all-knowing dog trainer. Yeah, right. Countless years ago when we adopted a Golden Retriever puppy, my mother ended up with a couple of dog training books to aid our transition to a household with a well trained dog. It was hardly her first dog, or our first dog as a family. However, she'd never been quite satisfied with the training results of previous dogs. Hence, the training books. One of the books gave a suggestion that she has been using ever since. Fill a tin can with pennies or small rocks, tape the top shut, and then shake the can, or even throw it at the dog, whenever the dog is doing something you don't like. Is he sniffing along the edge of the counter? Shake the penny can. Is he inching his way into the forbidden dining room? Shake the penny can. As I recall, this seemed to work for the golden retriever we had for so many years. It bothered her enough to stop the behavior without traumatizing her. Of course, she was a very laid back dog. We don't have the golden anymore, instead I have a German Shepherd. A GSD who is in no way laid back. He is a moose. He makes up his own rules and then breaks them at will. He is more than handful. At the same time, he is a generally well behaved dog, with a few exceptions.
He has never understood the no dogs in the dining room rule. Then again, we have never truly enforced it. He thinks the rule is more along the lines of no dogs in the dining room while the humans are eating. It seems to work for us. What does not seem to work for us is the penny can. Now, he is not a dog normally traumatized, or even vaguely bothered, by loud noises. We had a short bout with Thunderstorm fears when he was a pup, but he seems to have outgrown it. As we all know, though, for every rule there is an exception. My GSD's exception is the penny can. It terrifies him. All one needs do is pick it up while he is watching and he'll tuck tail and slink away. Shake it and he'll avoid that room/object/person/behavior for at least a day. Actually throw it at him, and he mentally shuts down for a day. I can't explain the affect it has on him, I can only observe it. And I can't say as I particularly like what I observe. If it is scaring him that much, he's obviously not going to learn anything from it.
Case in point, in the past several months he has manifested a new behavior where he sneaks upstairs (another place he is not allowed) any time we sit down for supper. In the past, he was expected to stay out of the dining room and not beg or whine. He always did just fine with that. In the ever optimistic dog's mind that he has, he did sleep on the rug just outside the dining room in the hopes of catching a stray carrot, or something. In the past several months, though, as soon as we sit down for supper, off he sneaks up stairs. And not in the sort of "I know there's something upstairs I can get into while they're busy paying attention to their food." No, this is the sort of "I know it's not safe down here while they're doing the food ingestion thing, so I'll go where it is safe." Why does he suddenly think the downstairs is an unsafe place? I'm not entirely sure. See, I don't have the opportunity to eat supper with them every night, which is fine by me. However, it means I don't see their behavior every night, so I can't judge what it is they're doing that has changed my GSD's behavior. And I know it's something they've done. Considering that I have noticed the reappearance of the penny can, and I've heard my mother say that if my GSD doesn't learn to stay out of the dining room then she'll be using the penny can a lot more, I can only assume that she has been shaking the penny can at supper time for some reason. Perhaps he has been inching his way into the dining room as is his wont. And as far as she's concerned her tactic has worked. He's not in the dining room, or trying to sneak into the dining room. Instead, he's hiding upstairs (another place he's not allowed) in a very unhappy state.
I've explained to my mother that I don't like her using the penny can. It is not an appropriate training tool for him, and it only makes him tense and more apt to react with his teeth, which is already enough of a problem. She doesn't understand, though. All she knows is that when she uses the penny can, he stops whatever behavior offends her for a few days. She doesn't see the way it harms her relationship with him, or the fact that it simply makes him an unhappy dog. Every time she starts using the penny can more often, I am forced to increase my training to regain his confidence. It works amazingly well, but I shouldn't have to do it in the first place.
Why do I bring this up today? Because twice today my GSD has come slinking up stairs with tail tucked and ears flat to his head looking for safety. He's licking his lips, and yawning, and giving off every calming signal I'm aware of. And it's all I can do to convince him to come back downstairs. Why is he acting like this today? Because mom has not one, but two penny cans strategically located on the couch. He has a bad habit of sleeping on the couch at night. I used to let him, but mom doesn't like dogs on the couch so I've had to curb the habit. Except, it hasn't totally worked. I've tried a couple things, mostly involving making the couch an inaccessible or uncomfortable place for him. Mom says either that the method isn't working, or that it's too much work for her. Putting a baby gate in front of the couch: too much work for her. Putting two penny cans on the couch: no work at all.
Now my GSD is afraid of the living room. So, he can't go in the library because it is under construction. He can't go in the dining room. He can't go upstairs. He can't go in the kitchen whenever my mother (or father, or sister, or random stranger) is annoyed by his presence. That leaves him with the hall and the living room. And she just took away the living room.
Now I get to try one more time to explain to her that using penny cans is unacceptable. But it can't be wrong. She read about it in a book. A dog training book no less. How can anything written in a book be wrong?