Just imagine a powder, that could make thing eatable (like swords or rocks).Try it an it will be verry funny.Just imagine..characters will need to get some information from someone. And if he will saw, as one PC is eating his sword.
Faerie foods with unusual effects. Like faerie sausages that turn the eaters into wiener dogs, faerie wines that make the drinker whiny, etc. There's a table in Palladium Fantasy RPG which has a table of ideas.