This may be passsive aggressive, but it sure as hell worked on me. I started praying... alot.. even talking to my Mom, yes she is deceased, she doesn't answer, so don't be alarmed. lol. I wondered, "What would my Irish Mother do?". My Mother was very warm, but very strict at the same time. She had a way of making you believe what she said was actually good for you. I would rail against her, but then, come to think of it.. she was probably right and whatever it was could come to no good end, and I would see it in her logical no nonsense way. (May have taken hours or days, but I came around).
She would do this thing.. it was like magic, even on neighbors kids. (I never had to use it on my SD's-grown), but she would make her point, firmly of course, and without much drmatics attached to it, then carry on doing dishes or whatever she was doing. She would not speak a word to you unless absolutely necessary, other then.. ummm mm hmmm.. and continue on. Until you caved, and 5 girls (sisters) always caved. She never once hit us, and not one of us suffered a bad grade or a detention or trouble with boys or the law etc...
I know.. It's a little Tiger Mom.. but I think I will try that... maybe she answers afterall! God I miss my Mom!