A jar of maggots is an essential item for dangerous journeys. When applied to a wound the creatures will eat the dead flesh, keeping it relatively clean and resisting infection.
They may likewise be applied to food which has become unwholesome, although of course this is only useful if there is some part which remains sound.
They are especially useful in the underworld, where damp, mould and a scarcity of clean water are accompanied by an unnatural tendency for all things to rot and decay.
Some magic will produce a walking corpse, which maggots will begin to consume if they are cast upon it. An entire jars' worth of maggots can cause such an abomination to act as a natural creature would act if set on fire. The products of the boker's craft are immune, being dead inside and alive outside rather than the reverse.