God forbid! wash your mouth out another here taught by Catholic nuns absolutely no slang or profanity of any kind, even the mildest would have been positively vapour inducing.
I went to Grammar School in 1948. All the teachers were definitely from the upper classes. Some were quite ancient but young or old they came from the same mould. They wouldn’t know what slang was if it was repeated and explained, it would have been irrelevant in their lives.