Kjs, that's typical of what USED to go on around here, but here's my new tactic: I tell difficult child that he may not speak to me like that. (I use a calm voice.) Then, later in the day when he wants a treat, like baseball cards, a Reese's Peanut butter cup, or some TV, I say, again, in a nice voice, "Oh, that sounds really neat, but no, you can't because you weren't nice to me this morning. Try tomorrow."
It works!!!!