I fail at reading comprehension. It was a funny joke, just not as funny as if it were real.
Does anyone actually weight 20-sided dice? I confess I've never played D&D, but I have made weighted dice for magic tricks. The easy microwave trick for 6-sided dice isn't going to work, at least not reliably enough to be worth doing, you'd have to do the stick-lead-or-something-in-the-pip thing, and with the pips being digits that would be a pain in the ass.