Thanks for the links Shaun, I'm intrigued by this recipe from your first link ;
Reduces high fever, as in the case of pneumonia. Crush and mash a whole, live carp and mix with a small amount of whole-wheat flour. Spread this mixture onto oiled paper and apply to the chest. When treating pneumonia, drink 1 or 2 teaspoons of carp blood, only in the case where the carp has just been killed. Take the body temperature every half hour, and immediately remove the carp plaster when the temperature reaches normal.
Surely not a whole, LIVE carp! : Kill it first, employ the services of a Priest.