When I tell him no, he stops.. for a few minutes. I'm not sure how to 'punish' a dog. If I put him in the crate for a few minutes, he'll chase his tail in there. I've seent it, I've seent it. He's a stubborn butthole who likes to chase his tail.
Is spraying that icky tasting stuff on his tail an option? Hahah. I don't want to think about chopping his tail off. GSD's have awesome tails, so..