Bonus trivia

Why did this work? I’m no chemist, but I have a hunch it has to do with citric acid, the fourth ingredient listed on Monster Energy’s label. Citric acid is known to be a good cleaning agent for bathrooms and hard surfaces, and its low pH of just 2.2 means it erodes many substances, including, apparently, rust. This means that other beverages high in citric acid just might yield similar results.