To add, it's worth noting that "snake oil salesman" was a very real thing in the 19th century[1]. It is pretty hyberbolic to assert that there's more figurative

To add, it's worth noting that "snake oil salesman" was a very real thing in the 19th century[1]. It is pretty hyberbolic to assert that there's more figurative snake oil salesmen when there were once literal ones. [1]: https://en.m.wikipedia.org/wiki/Snake_oil https://en.m.wikipedia.org/wiki/Snake_oil