Since your dog seems ruled by his stomach, a friend came up with a helpful suggestion. She said that clicker training stay might do the trick. When the dog hears the click of the clicker, he's taught that he gets a treat. Apparently, you can then use this as motivation for the dog to do what he's told, because if he obeys a command it makes you click and he knows he gets a reward.
The idea took a bit of getting used to, but so far so good. He's still no furry angel but at least his manners are improving a little...
In the case of 'stay' the desired action is clicked so that the dog understands it's not moving that is about to be rewarded. Thus, the dog hears the "stay" command and knows that playing at being a statue will earn a reward.
It is, however, important not to throw too much information at the dog in one go. Start training in a simple way with expecting the dog to stay still for a certain amount of time. Once he has gained this level of self-control, then you can start to add a bit of distance by stepping away from the dog.
You need very little basic equipment to teach 'stay' and remember, if you don't have a clicker then you can use a retractable pen to make a clicking noise, or even make a clicking noise with your tongue.