Shellawax is a friction finish that can be used by itself or with other finishes. Friction finishes are easy to apply and look good but don't last long. I use CA, about 10 coats, level off with 500 grit then MM, then plastic polish.
Some oily woods don't like CA. On those I apply Shellawax or Mylans when a few coats of wipe on poly on top of that.
I'd stay away from Crystal Coat by Hutt. It has a very short shelf life and the finish on a pen doesn't last as long as other finishes.
My money talks to me... It says Good Bye.