I gave up. I bought the dog his own cat food. He really likes it, which is huge for him, and he eats it happily when presented with it, and its not "bad" for him - it is much higher in fat and protean than dog food, and under normal circumstances, this would make your dog fat . My dog is not fat, my dog looks like a whippet! My dog is supposed to look like a weimaraner! My dog will be okay with some cat food in his life. I will transition back to full on dog food, but for the time being, I can find the Fancy Feast pretty much everywhere they sell pet food and after working really hard to find his dog food, I find this refreshing. And cheaper.
His new dog food is hard to find and expensive when it is found. I think what I may very well try out is a half dog and half cat food mix , until I run out of the good dog food and then maybe try a full on cat food diet for a bit. He is getting fixed this week and after this he will "need" fewer calories - he all ready gets fewer calories! I'm actually looking forward to the dreaded weight gain.
Today was a better behaiver day. I kept the cat upstairs to see if having him out of dight would make a difference, and today, Rocket didn't destroy anything, all day. Tomorrow I'm going to leave the cat upstairs again and have Rocket spend the day with the last day of free Dog TV.