For trouble with sleeping a raw onion eaten before retiring has been found to have beneficial properties.
This belief goes back several centuries.
Onion syrup is supposed to be the best treatment for severe colds. Peel and slice an onion, sift sugar over it and let it stand in a warm place until the sugar draws the juice out. Take a teaspoon as needed.
Bathe burns in onion juice. The juice is suppose to take away the heat of scalding with water or oil.