This does work... I have used it before when I had cough that won't go away.
I followed the directions but I used a paper towel instead of cloth. Don't skip the part about vasoline on your chest... This will burn otherwise. The strange thing is that it does not heat up until after its been on your chest for awhile. Another suggestion I have is if you are planning to do this take the egg out of the icebox and let it come to room tempature. Otherwise it will be cold against your skin.
Flour, Dry Mustard and Egg White
Cough and congested chest remedy. Three teaspoons of flour, one teaspoon of dry mustard and an egg white. My mom has a great remedy for a cough and chest cold. Three teaspoons of flour, one teaspoon of dry mustard and an egg white. Make a paste of theses ingredients. Then you should spread it on a white hankerchief or something very light weight and I assume dye free. YOu then should rub your chest with vaseline. (The paste is exothermic and can burn your chest.) After that you should place the hankerchier (with the paste foled inside) on your chest. Every so oftern chekc to see if you need to apply more vaseline (to prevent burning). Dress warmly when you rest and I promise when you wake up , you will be cough and chest-congestion free. My mother always did this for my nephew and I just did it for my 11 month old. He had congestion for a week, and the night I did this (after over the counter medicines) my son no longer had congestion or a cough. Try it. It really works.