For centuries mustard plasters were the tried and true home remedy for the flu, coughs, colds, pneumonia and many other ailments. It was used regularly up until the not too distant past since this poultice was thought to sweat out all the “ills” the body held.
A mustard poultice is a time-honored therapy: Your great-grandmother may have used mustard poultices and plasters to treat congestion, coughs, bronchitis or pneumonia. A mustard plaster offers immediate relief to discomfort in the chest and actually helps to treat infectious conditions - a much needed therapy. It works mainly by increasing circulation, perspiration and heat in the afflicted area.
The person receiving the treatment should sit or lie down comfortably. The best poultices are made from black mustard seeds ground fresh in a coffee grinder, but ordinary yellow mustard powder will do in a pinch.
To prepare a mustard poultice, mix 1/2 cup mustard powder with 1 cup flour and stir hot water into the mix to form a paste. Spread the mixture on a piece of cotton or muslin has been soaked in hot water. Cover with a second piece of dry material. Lay the moist side of the poultice across the person's chest or back.
Leave the poultice on for 15 to 30 minutes; promptly remove it if the person experiences any discomfort. The procedure is likely to promote perspiration and reddening of the chest. Give the individual plenty of liquids during the procedure and encourage her to take a warm or cool shower afterward, then rest or gently stretch for 1/2 hour.