I'm from Mexico, and every time either my grandmother or mother bought a new clay pot, they started "healed" the clay pot by boiling water with vinegar, rub garlic on the outside of the pot, and let it rest all night long.
I recently bought a clay pot, and it released black particles into my food. I asked why, and my mother told me it was because I didn't "heal" the pot.
I thought it was ridiculous, so that made my wonder if it's truly necessary to "heal" a clay pot, and if this belief is endemic of Mexico or is it also well know in other parts of the world as well.
Hope this question isn't off topic. And if it is, feel free to flag it.