I will say, at least in the early episodes, they used a ton of human remains. Call me old fashioned, but I’m not sure it was a respectful to punch actual human skulls until they crumble for pure entertainment and the sale of ad time.
If my skull getting punched until it’s dust is what it takes to get even one American to get interested in science I would consider it an honor.
Presumably after you’re done using it.
Either is fine