Here's another fabulous home remedy from my librarian friend Marie. Her family's recipe book contained this gem that sounds kind of scary, but possibly effective.
Onion Syrup (A Cough Medicine)
One or two onions, sliced -- enough to fill a cup nearly to the top. Sugar as needed.
Take large coffee cup, put layer of sugar in bottom, then fill, alternating slices of onion and layers of sugar. Place sauce upside down to cover top of cup. Invert cup, sauce and all, carefully, so top of filled cup now sets in saucer. Place in warming oven or on back of wood-burning kitchen range. In a couple of hours the 'syrup' will begin to seep down and fill saucer. Give one or two teaspoons syrup as cough medicine as needed. Prepare a new cup to make more syrup when this one slows down.
Note: This was prepared by a practical nurse and they tell me it saved my life when I had the whooping cough at 18 months in 1920 and the doctor had given up. Need-less to say, my mother used this remedy on the family for many years.