These are beautiful slim knives (which makes it so easy to do the ‘paddle move’.) You get two of them. Many changes are possible. Change a white knife to a dark gray knife and a dark gray knife to a white knife. Then make it disappear and reappear in your pocket.
Is it dark gray or is it white? It's gray. No, it's white! When you think they've had enough, make the knife completely vanish and reappear in your pocket.
Go ahead, pass it out for inspection, they'll get even dizzier when they see it's just a plain old everyday knife.