The first hone I ever had was my grandfathers Little Frictionite 00!

It came with directions, a green cloth case and the rubbing stone!
According to the printed directions the rubbing stone is used to remove any swarf that has built up on the hone surface, and it works very well for that job. It also functions to "refresh" the hone surface.
IMHO the coarse side is for light touch ups and the fine side is a finishing side. In the past they have sold on Ebay for over $100. ( I have 2 of them!

).
Hope this helps,
