@tsarstepan,
From our association with a friend of ours from Vietnam, that a few years after his getting to the US, went back to his family roots, Chinese. We stayed at his house once, and he offered my husband some of his concoction (I forget what it was called, but it was to help us have a good bedtime session). Oy. Anyway, I take it that a lot of this potion stuff is from long time superstitions, which are hard to get rid of, for many humans. I suspect they are costly for the buyer as well as the animals, part of why this stuff keeps happening.