I had to do this with a child recently. I used his bed as a punishment which I NEVER do. Bed is a safe spot. He hated bed though so I had no other choice
. I felt terrible but he was also displaying violent behaviour and hitting and my usual firm voice at eye level and taking away priviledge tactics were not working at all. It nipped it in the bud right away. Within a month the violent behavior went away completely by just sending him to his bed twice for a few minutes and then threats to be sent there. “If you hit you will be sent to your bed” or “and what happens if you hit”?...sets expectation and then follow through if non compliant.
Sometimes you have to undo a LOT of bad parenting in a short amount of time
I don’t mind working slowly with other behaviors but violence is not tolerated at all.