Discipline does not work any way, shape of form for training a dog, especially not a very submissive dog. Positive reinforcement is the only decent way to train a dog. House training a dog is the easiest thing to do. All you have to do is take them out a lot at the right times and praise them when they do what they are supposed. IF they do make a mistake, the word no, followed immediately by taking them out is how to do it. A person has to be smarter than the dog to train them. However I do not see that there is really a house training issue here. It sounds more like the dogs just gets excited and urinates in the wrong place, which I do not think the dog can help.
Obviously he would be easy to "catch in the act", since he is doing it right in front of the people. He has no control over this action. No dog wants to pee all over like this. I would recommend ignoring it, cleaning it up, and praising the dog for correct behavior. Young dogs do this urinating thing often. Usually it will pass with time and the right action by the owner. A year old for a boxer is still young. I would suggest exposing the dog to more stimulation and more people so he gets used to it. I think with time he will get over this behavior.
It could be possible to beat or disipline a dog into any thing you want to teach it. You will end up with a dog that needs a dog psychiatrist. You will not end up with a loving pet.