This thread reminds me of an old story I read somewhere, years ago.  Maybe
someone else remembers reading it.  Someone in the U.S. had been promised
some golden cowries by someone in the South Pacific area (you can see I'm a
bit fuzzy on the details).  Months went by and the promisee was beginning to
wonder if the promise was for real.  Then one day a parcel arrived.  He
eagerly tore off the wrapper and opened the box.  Inside were a half dozen
large Cypraea aurantium - each of which had been tossed into the fire and
cooked in the shell.  Once the meat was extracted, the shells were sent to
the collector.  I can't verify it, but I always remembered the story.
Paul M.