No need for hexane at all.
Take wheat, grind it into a fine powder commonly known as flour. Use no modern chemicals, use only a mortar and pestle. Grind it very, very fine.
Take a handful and toss it up into the air in a closed room above a lit candle.
Oh, BTW — make sure you have medical insurance and your will kept up to date before you do this.
Very funny! Grain elevators have had some nasty explosions cuz kids played that game, eh? ;-)