I don’t think House was ever trying to help anyone by being mean? He was just arrogant and self-assured, so he knew that even if he was rude and assholish, it would pay off because he would save someone’s life and that would justify his behavior for those people and those people would in turn then find him endearing and likable. In short, he knew how to use his charm and intellect to get what he wanted the most, a fix for the pain he felt, literally and otherwise. At least that’s how I interpret his behavior, but of course like any good piece of writing there can be different interpretations.