I've associated this with the American Old West, but perhaps the second definition originated in the really old, old west...snake oil
NOUN: 1. A worthless preparation fraudulently peddled as a cure for many ills. 2. Speech or writing intended to deceive; humbug.
Spell May Comprise Oldest Semitic Text
-gailr...
Believing that some snakes spoke the Semitic language of the Canaanites, Egyptians included the magic spells in inscriptions on two sides of the sarcophagus in an effort to ward them off.
"Come, come to my house," reads one section in the Semitic language that is supposed to be the snake's mother speaking, trying to lure him out of the tomb. In another passage, the snake is addressed as if he is a lover with "Turn aside, O my beloved."
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The text includes words that have the same meaning as in Hebrew, like "yad" for hand, "ari" for lion, and "beit" for house, he said.
Hmmm, did JK Rowling mine even the KMT for her snake charmers?