Will Miss #451 - bizarrely inappropriate English lessons

An infamous video lesson teaching people the phrase "I've got a bad case of diarrhea". 

One of the textbooks that I used to teach from had a lesson about slicing cheese. A waggish teacher crossed out "slicing" and changed it to "cutting". When the students did the pattern practice, they would mechanically talk about cutting the cheese as the teachers sat by and tried not to laugh. The thing