There have been some binsui jnat stones on ebay, item #200422233034, they come in a courser red which is estimated at between 600-800 grit and a white at 800-1000 grit. I was wondering if anyone here has used these or if anyone thinks that they might work as a natural bevel setter. The ad says they are used for removing damage and rust from chef knives and such but makes no mention of razors, I am wondering if they might be a little rough for a fine edge like on a razor. Would I be wasting my money? Thanks.

-Jason