I thought I'd share the process and some of the end products here in case you'd like to give it a try, too.
Make sure there are no gaps in your design. I occasionally used cut pieces of the snake and stood them on end. These created dots when shaved. Above right is an example of a snake design.
The sample below shows the shaved snake design made from the same colors as the example to the right. When the tops are shaved off, all the various colors from the extrusion process come to light.
The next two sheets - one with yellow background and one with green - show random placement of the shavings from the snake design. I love how changing the background changes the whole tone.
Finally, below are a couple more photos showing shavings on a purple background, the snake design sheet from which the shavings came, and a piece cut from a snake design using a wider circle hole in the extruder.