I sympathise with you OP.
Most people cannot imagine what it is like to have a violent child.
My DD 13 is autistic, PDA and our lives are completely ruled by her violence. Even when she is not being violent, we are carefully tiptoeing around so as not to trigger her.
DD has been violent for most of her life, but of course, as she has got older, she has grown stronger and I'm sorry to say that we have no answers.
DD has a diagnosis, an EHCP, and I believe social care, where she is registered on their disability team, are doing all they can, but they cannot stop her being violent.
I have read the explosive child book, I have completed parenting courses, I have engaged with social care, yet we are still left to deal with the fallout every single day, and this seems to be the case for the parents of the violent children i know.
DD punches, kicks, bites, headbangs, pushes, claws at me and destroys my belongings. I am always bruised but more than that, I am now demoralised and exhausted with it.
DD doesnt only resort to violence, she also humiliates and verbally attacks me too.
She is far too strong to control and requires at least 3 adults to safely hold her.
It feels like I'm being bullied in my own home every single day.
Most people have no idea how impossible it is.
The police are reluctant to get involved, because DD has additional needs. Yes, that's what the police said when I called 999 because she was beating me and I had locked myself in the toilet to escape her.
Our only option now is a residential school, but from the ineffective and barbaric way I have seen her managed at special schools, is not an option for us.
DD has zero empathy, cannot see anything from another's view point, feels no remorse or embarrassment, has no patience, is excessively controlling and doesnt actually want to change, because let's be honest, being violent is an effective way to get other people to succumb to your wishes.
Just writing these few words doesnt nearly describe half of what it's like.
So, imagine you are living with a fully grown violent adult, strong and intelligent enough to understand when you are trying to distract them, but they are determined to have whatever they want at any cost, and if that requires manipulation, threats, humiliation, threat of damage to your things or violence, then that's what will happen.
What would anyone suggest? They certainly wouldnt suggest reward and punishment (ineffective with DD) because this is a grown adult and who are you to attempt to control them? No one would suggest you approach a fully grown violent adult and remove what you class as their privileges, or insist they sit somewhere and calm down.
None of the standard behaviour management techniques are effective with a violent adult, which is why so many DV victims turn into shells of their former selves, and live their lives in fear.
If managing violent behaviour was this easy, we wouldnt have half as many womens aid shelters, because the victims could just get the man to sit on the thinking step, or avoid his triggers, or remove his privileges, or explain how his behaviour is making you feel.
But this doesnt work, and this is the reality of living and loving someone who is regularly violent, controlling and manipulative.
Most people would run for the hills, because that's sensible, but this is not a violent bully of an adult. This is your child.
OP, The only solution I think works is to remove the child from the situation. This usually means a residential school. I am not ready for that, but I hope I dont regret passing that up at a later date.