I think the OP is referring to carrying a small knife into the Disney parks, not on an airplane.
I would leave the knife in the room. There are apple corer/slicers that are available. It's the circumference of a normal apple with eight slicers and a round hole in the middle to core the apple. It has small handles on each side. You put the corer/slicer over the apple and push down. The result is a cored apple in eight slices. It's definitely non-lethal. You can get these in any Wal Mart or stores like that. And you will find if extremely handy around the house as well. No more knives to slice your apples. Excellent for making apple pies.