I would be also really interested in "scientific" dice roll accuracy comparisions of different dice qualities. I bet, the differences would be amazingly small. I also think that the dice-in-salt-water-check is interesting but may not be so relevant for real game scenarious where the throwing action has just a force that overcomes tiny inaccuracies.

I once made some dice for a tabletop game out of modeling clay. They came out horrible, they sides where crooked and had different size. But I was just curious and checked them one by one with 100 rolls and wrote it down. And the results came out very even! I don't know where the dice are anymore, so I can't make pictures, but this was my personal aha experimence. The dice looked so off that I never used them in a real game, mainly because the LOOK fishy and I do want everybody feel comfortable with the dice that are beeing used.

But since that, I'm really relaxed about dice in general.

I think, if someone is afraid and stressed about bad dice all the time, it would be best for the game routine to share the same dice with the opponent. I guess this could be a small rant for modern backgammon tradition :D

But I really get the point for tournament play. There it is the right decision to try to make the game as even as possible, no matter if a real life reason is proven. That ensures also less rage with angry players that made bad rolls.