Bring a large saucepan of salted water to a rolling boil. Add the rocket and blanch for 1 minute. Drain the rocket and plunge in iced water to refresh. Squeeze as much water from the rocket as possible. Lay the blanched rocket on a dehydrator tray and dehydrate in a food dehydrator at 55°C (130°F) for 48 hours.
Remove the rocket from the dehydrator and place in a vita-prep (or high-spee