Even so, I did wonder about that Witch in a Bottle, as the artifact appears very close to traditional folk counter-witchcraft magic.
The bottle containing links (both constructed and physical) to the 'witch' would be in ways akin to a poppet or other simulacrum, and so be bound to her vital essence - thus in a sense 'trapping' her. Which perhaps, is where the item gained it's local reputation as containing a witch from?