#9: Wearing a Mustard Plaster for Chest Congestion
This “old wives’ tale” made it into the mainstream medical system in the 20th century, with brands like Johnson & Johnson selling pre-packaged mustard plasters you could pick up in your local pharmacy. And while this practice has endured through the decades, it’s not entirely safe. If a mustard plaster is left on for too long, it can cause nasty skin burns or uncomfortable irritation.

