What did they do to the maneki neko before I purchased it?

Hello! Sorry if this isn’t allowed here.

Yesterday I purchased a ceramic lucky cat from a shop near a shrine in Gifu. After I paid for it, the shopkeeper put some kind of gold coin inside the cat (there was a slot in its back, maybe it’s supposed to be a piggy bank?) and then she made sparks above it with flint or something. Was this a way of blessing the cat?

I can’t find anything about what she did online, so thought someone here might be able to enlighten me. Thank you!