What is the origin of the idiom "knock something on the head" and when to use it?

The origin of the idiom "knock something on the head" is uncertain, but it is believed to have originated in Britain in the early 20th century. It is thought to have originated from the practice of slaughtering animals by hitting them on the head with a hammer. This phrase is often used in informal or casual language to indicate that something is finished or is no longer happening.