I have never done that, but I did set fire to a balloon filled with hydrogen and aluminium dust. the result was an explosion over my head followed by fire raining down to the floor.
And to give you my opinion on your argument. The Zweihänder wins. The reach advantage is too great . With the Zweihänder you can literally create a wall of sword in front of you and charge him down. Just make a figure 8 movement with the sword and charge (this was used against pike formations). The gladius would only stand a chance in close quaters, the Zweihänder can still half sword then though. If you know you will fight take the biggest weapon you can still wield effectively. If it's a weapon of self defense that you would carry around all day the gladius is better, because you will have a lot of fun carrying a sword as tall as you around.
~edit: fuck formating. enjoy your wall of text
what is your favourite sword?