I used to say 'I can't understand you when you are crying/screaming/complaining/shouting/wailing/yelling/moaning. Come back when you can talk like a normal human being and we'll discuss it sensibly'. I never used to shout or scold that much unless I got really annoyed, just refuse to engage until they were talking and behaving like a rational person.
Also, specifically spell out consequences. Ask them if they want to do whatever they are saying no to the nice way or the nasty way. Go through in tiny detail all the bad parts of the nasty way and the fact that it takes three times as long etc (and then I'll tell you off and you will feel sad, and then you will shout at me and I'll have to send you to your room etc etc - OR, you can just go and pick up your clothes, put them in the washing basket, and come down and sit with me in the kitchen and have a glass of orange juice/watch TV, or something else not insanely good but still nice that the child will like - not chocolate, though I guess you could try it if orange juice or whatever didn't work). It is, after all, their choice.
Re answering back I would probably have said quite menacingly 'WHAT did you say?' or 'How dare you?' or something and sent to bedroom plus there would have been an expectation that they would need to come back and apologise before normal service was resumed. I would also always apologise if I realised I was being unfair or had lost my temper or whatever too, so hopefully modelling reasonable (if not perfect) behaviour.
However, you also have to have an iron will and don't give in for an easy life. The first time you will probably have to send the child away multiple times until a sensible discussion can be achieved. I spent hours once in a department store teaching a crying three year old that if I said 'we are not buying anything other than the thing we have specifically come for' I really really meant it and did not want to be asked for anything else (it was something nice for the child, so wasn't being mean!!). More than a decade down the line, this has paid off. If I occasionally spring for something unexpected I am treated like the messiah.