I’m finally back home and I have some video of me doing the trick with the Gozinta Boxes that I had been playing with. The effect is a production of two cups and then liquid to fill the two cups.
The beauty of the Gozinta Boxes is the misdirection, you can load anything into them. The first load, is easy as there’s not heat on it. The second one is still pretty easy to do and the misdirection is still very strong as people are reacting to the production.