This Naniwa Dressing Stone or also known as Rub Stone and Slurry Stone is for cleaning the surface of your waterstone/Whetstone.
Note from Phil: Soaking your rub stone for 15 mins prior to use is always a good idea. For those of you new to sharpening, you will find that as you sharpen you will see that your stone starts to get a black substance building up on the surface, and you will also notice you are not sharpening as quickly as before. This is iron/carbon build up that gets in the pours of the stone, natural or synthetic. Use the rub stone to remove this deposit so that you have fresh new material to work with.
Dimensions: 2.5″ x 1.8″ x 1.2” /65mm x 47mm x 32 mm
Weight: 7.6 oz / 222grams
600 Grit Stone
Made in Japan