I know nothing about autism.

One of my parenting strategies for stopping undesired behavior was to "reboot their brain". Versus scolding, punishment, etc. That usually means something physical. When timeouts stopped working on my minions, I escalated to pushups, then sit ups, then jumping jacks, peeking at wind sprints (running back and forth).

It's very hard for a child to continue being naughty when they're pumping iron.