Like Putting Lipstick on a Pig

Origin

The phrase comes from rural and agricultural humor, describing the futility of trying to "pretty up" a pig-an animal that’s going right back to the mud. It appeared in print by the mid-20th century and has been used across the U.S. ever since. The imagery feels especially Southern because of the region’s long association with farm life and plain-spoken wit, though it isn’t exclusive to the South.

Verdict: Southernish. A nationwide expression with a farm-born image and a Southern sense of humor.