I looked at those, too. It appears that you need self adhesive sandpaper in whatever grit you want to use, trimmed to fit the stainless sticks. Advantages might be that they are fairly thin and flexible, more so than plastic or popsicle sticks.
I added the flex attachment to mine a few years ago. Makes it sorta like holding a fat pencil. I found I have a little more control than trying to hold the bulky part of the Dremel.