Ive done pens using glitter in a similar fashion, not hard to do yourself but you will need to acquire some in tube molds. I found slimline not good for this, too little “meat” to the pen, preferred cigars and Wall Streets and the like for that.
I also have a tube of sand that I would like to have cast on a pen tube. Major significance to the Marine Corps. Your post has prompted me to seek someone skilled to craft the blank. If you find someone with whom you are satisfied let me know.