Review on Skull-Shaped Whiskey Ice Ball Mold Set: 6 Large Sphere Ice Cube Molds with 2.3x2.3 Inch Round Cubes by James Parker

The ice cube tray is easy (as can be expected for this type of ice cube) to fill and clean. You use a little funnel (they provide two) to fill the skulls - I found it helpful to press a little on the top/bottom portions of trays to keep top from rising (avoiding overfilling). Note that you can place the funnel into any of the four skulls and fill the tray - they are connected. By the second batch of cubes, I was making perfect skulls. I use bottled water and they are crystal clear. Product arrived quickly also.