123 magic scepticism

We have been recommended to go on the next 123 magic parenting course, for those who like me have never heard of it, it's a course on how to effectively discipline 2-12 year olds.
Apparently it's magnificent and will transform my daughter into a parent abiding toddler......
Or maybe the idea is to show us how to control our child as clearly we haven't been doing a good job??
It seems both pointless to me and somewhat insulting, if I was a first time mum I may feel less insulted, or if it was a course on how to handle your autistic child it may seem more helpful.
Having 6 kids has taught me one certainty, no one rule works for all kids, sometimes all the ideas don't work for one kid.
I may know fairly little about autism but I do know my child and she doesn't respond in the same way as other kids, you can't expect her to "fall in line" to help us discipline her.
Yes she needs reeling in, she's unpredictable and somewhat out of control at times but do they really think we haven't already tried? I'm already fed up of people coming into my house and effectively saying "there look she did what I asked while I was here what's your problem?"
All these experts are always ranting on about reinforcement, believe me I repeat the same requests every single day, "no ice cream for breakfast", "please sit down while you're eating", "no dummy during the day" etc
Does it make any difference to Freya?? Nooooooo
She can easily out-scream me, out-argue me and move a lot faster than I can to get what she wants.
By the time you've heard "need my dummy,need my dummy" fifty times without stopping to draw breath at full volume, you actually want her to have the damn thing!
I have never met a child whose scream is so piercing and it's relentless. The point of it is to get what she wants and she won't stop until she's got it.
I don't care anymore if she will do what nursery ask or someone who comes to play, I don't care if they think I'm stupid or useless for not being able to distract her onto something else to avoid a tantrum. The fact is she is full on hard work at home and it's not because I am lacking in parenting skills, it's because she can be, she can let loose, she gets bored at home and ignored as I sort out Lucas or try to get things done.
All that I'm expecting from 123 magic is to become extremely frustrated myself as someone tries to tell me these methods will work for my child. Added to the stress of finding childcare for Lucas, re-arranging Freya's nursery days so we can attend and then finding time to do homework!!
I'd even forgotten that I'd have to interact with other parents and listen to their opinions about discipline, (not one of my strong points) it's likely that I will end up offending someone if not everyone as I just can't listen to people spouting on about how we should all do things the same way, it's like a parenting cult!
I wish I'd just said I didn't want to go but I always feel I don't have a choice, like just saying thanks but I don't feel it will help makes me a bad parent. What do I think is going to happen then? That they will whisk her off to another family? Some days I wish someone would just for a day!
Perhaps I will be pleasantly surprised and some of the suggestions will help us with Freya but for now I'm not looking forward to the experience one bit!