The best cough syrup I ever used came from an Iranian doctor friend.
Onion Honey Juice
Slice 1 -2 onions that have been peeled
Place in a casserole dish or large mason jar.
Cover the onion with 1/2 – 1 cup honey.
Cover dish or jar and let sit overnight.
In the morning take 1 -2 Tablespoons every couple of hours.