A childhood belief about speaking

I've often heard of "taking something too literally", but do we ever hear of taking anything too figuratively? Well, I have done precisely the latter. Growing up, I repeatedly heard the phrase, "Go wash your mouth out with soap and water!", spoken, for example, when someone had said a "dirty word". I always thought that was clearly a figure of speech, and that surely no one had ever been literally required to do that. It wasn't until my first part-time job during college that I heard a co-worker speak of how her mother used to make her wash her mouth out with soap and water. Something about the context in which she was telling it seemed to indicate that her mother made her LITERALLY do that. So I asked her, and she assurred me that indeed her mother used to make her LITERALLY wash her mouth out with soap and water. I was astonished to learn that that was ever more than an outlandish figure of speech.