Had a bit of a play about with this. We demo the whoosh bottle using a water cooler bottle. very effective. However i was wondering if you could use the same raction to launch a rocket! Well you can! Use a 3 litre PET pop bottle. Pour in about 5ml of ethanol and give it a really good shake so that the whole inside of the bottle is 'wet'. Invert the bottle on a clamp stand (put the vertical rod up inside the bottle). Use a long splint to light the fumes at the bottom of the bottle. The rocket launches with a very satisfying whoosh and leaves behind a very impressive pool of flame as the excess ethanol comes out the bottom (did I mention to put the clamp stand on a bench mat)? Not as noisy as the Methane rockets so no need for ear defenders and a proper flame!