from the Farmington Observer January 6, 1977
It is generally thought that the use of a lead poultice on Beethoven is what led to his poisoning from the metal and ultimately his death. Obviously with the acquired knowledge that the possibility of heavy metal poisonings could occur (Wow, just as I was typing this one of the snow globes I bought for my daughter while she was in utero 3+ years ago started playing "Hark! The Herald Angels Sing"; no Beethoven but odd nonetheless since I haven't wound them in at least a year. Very strange!) the organic forms of bread and cereals became prominent. Native Americans sometimes used pumpkin for their poultices while others have used bran and ash, among other things.
Whether they work or not probably depends on the severity of the virus and the person its administered to but it's a nice, natural alternative to antibiotics which seem to be the main "healer" of the day. If nothing else they are not harmful (the food grade ones anyway) and will only cost you a worn rag or well-used article of clothing and the other materials used.