Brit Dopers: origin of this phrase.....

In romance novels, primarily the Regencies, there is a phrase that I know what it means, but I want to know exactly where it came from and all my searches have come up dry.

** To stick one’s spoon in the wall ** : means to die, but…well…I don’t get it.

According to bartleby.com:

But it’s using Brewer’s Dictionary of Phrase and Fable as its source, and I’ve been told off for using that before now on these boards.

Thanks, everton.