Heavier things DO fall faster! Just try to drop a feather and a stone - you will see :)
Seriously, just compare how science looked BEFORE Aristotle and AFTER Aristotle. Then look at the science BEFORE Newton and AFTER Newton. Then do the same with Einstein.
Aristotle is the greatest in science, even if Plato is a greater thinker. See my tagline.
I just did that in my vacuum chamber and it was a tie. Then I jumped out of a plane with my parachute and dropped a brick at the same time. The lighter brick beat me to the ground. Then I got into my time machine and went bach to ask Aristotle why that was. He was still scratching his head when I left. Just to put in a plug for Einstein, I gave him a flashlight that charges with solar cells. He was still scratching his head about that, too. I've had a busy evening.
Aristotle set the stage for Newton, sure, but for clearly explaining motion, Newton is the man. Yes, Einstein's work allowed amazing things to be developed, but I'll still take Newton.
An easy "quick and dirty" demo ( which I thought of myself ) is to put a piece of paper, say, and a penny on a large book such as an atlas, and drop it to the floor. Of course, they keep their place on the book as they fall.
It might be objected that the paper is being "sucked along," but if you watch closely, you can see this is not the case. It remains in quiet air.
( Be sure to warn others who might be alarmed by the thud ! )