This Man-Made Nagura is an effective and inexpensive means of keeping the surface of your waterstone clean and free of glazing. Rubbing the wet Nagura across a wet waterstone creates a slurry that cleans the stone. Evidence suggests that the Nagura can help keep the waterstone clean when sharpening, as well as preventing it from drying out and sticking to the steel. Some Nagura users believe the slurry itself actually does the sharpening, while others think the slurry keeps all but the highest points of the stone from touching the steel, in effect making a stone much finer.