I'm not sure that corn starch would stay as a fine powder long enough for that to work. However, if you have a long cardboard tube: * place the tube verticall

I'm not sure that corn starch would stay as a fine powder long enough for that to work. However, if you have a long cardboard tube: * place the tube vertically with an ignition source at the bottom (small candle perhaps) * pour fine powder in the top (may need a step ladder if the tube is tall enough) * satisfying whoosh Don't look down the tube as you are doing it and don't do it indoors, obvs!