The set up for this is as follows: I have an old lightbox (for viewing slides actually), that I picked up used, with a 77 mm Hoya polarizer on it. The fork is a cheap plastic disposable utensil. I used a knife and a spoon as well, but I liked the fork the best. I used my Tamrom 90 mm macro lens with another Hoya polarizer (58mm) on it.
The magic happens as you turn the ring, the background goes black. This is the same way that variable ND filters work: two polarizers "cancel" each other out and block the light. One recommendation: clean the utensils often. Very often. I ran into the Lightroom problem of slowing down with too much use of the spot removal tool.
