I have a couple razors that have lots of chips along the blade, or have an uneven blade (warped, not smiling). My norton 220 and 1k don't seem to be evening things out. Is there a different type of stone that would work better? I think some have mentioned a DMT diamond stone. Can you get those at Lowe's or Home Depot? What grit is good? Or should I just stick with the norton?