This is really "just" a suggested experiment to test whether or not an idea is possible, not a fully fledged propulsion concept. The idea is to place two thin and very smooth plates very close to each other, at a distance where the Casimir effect takes place, but with a twist. The twist is to temporarily magnetize the plates at exactly the moment they are pulled together by the Casimir effect, causing the magnetic field to act in the same direction as but much stronger than the Casimir effect.