To clarify: The tricks by Elliott, Hunter and Sellers used an imaginary die (and a different plot, using a matchbox to predict an outcome of one to six). "Ice Dice" used a physical prop -- two cubes made of transparent acrylic.
In the write-up, I also suggested that you could use blank solid-color cubes (not difficult to find in various children's game sets), or sugar cubes, or actual ice cubes, or imaginary dice.
I'm not claiming any great conceptual breakthroughs here, just noting that, so far as I know, the visual gag of spotless dice was first put into print by me. The only real advantage of this idea over an imaginary set is that you get an extra moment of amusement when you initially bring out the dice in your fist, and rattle them. The audience hears the sound, envisions normal dice, and is thus surprised when they turn out to be transparent.