Is there anything more effective then Onion juice for bad Colds and Flu?

Recipe: Take one Medium to Large Brown onion, peel and dice. Place in a bowl, sprinkle one tablespoon of sugar over the top. Cover with glad wrap and leave on the side overnight. In morning Drink juice.
You will need to prepare more then one bowl for the effect of the first bowl's juice will wear off after a couple of hours.
Tic Tacs are a must!