The trainer said to us that we need to ask nixon to do something ONCE, and if he doesn't do it, we go over and force him to do it. He will never get a treat, but he will eventually learn that if he doesn't do what we ask the first time, he'll end up doing it anyway because we'll make him, so eventually he'll just start doing it. He said that's the only way to really get Nixon to respect us and to respect our things and know that he can't touch or destory them. We've done well with some aspects but not as well with others. It's so much work and requires a lot of time and honestly, it's our fault that he isn't as obedient as he should be. We do the best we can though.
The trainer also had some other interesting methods of training that I wouldn't necessarily recommend. For example, he said one of his dogs (he has a ton of dogs and he does training for the CIA and stuff) used to eat high heels all the time. So one time he shoved a high heel in its mouth and put tape around its head and left it like that for hours. When he took it out, he said that dog has never touched another high heel! Interesting.