"Wash your mouth out" is a phrase that is commonly used to indicate that someone has said something inappropriate or offensive, and that they need to clean up their language. While this phrase is still widely used today, there are several other synonyms that can be used to convey the same message. Some of these include "watch your language", "mind your tongue", "be careful what you say", "clean up your act", and "check your mouth". These phrases all communicate the idea that someone needs to be more mindful of their words and avoid using language that is inappropriate or offensive to others.