- North of Cincy OH
did a lot of search on this in the past.... best route seen so far that are more of sipes and less of a groove of various sizes is with a hot grooving tool.... with the hot cutting portion flipped upside down to the thin side. some of them are even twin blades on the opposite end of the swap-able grooving head. seen some who did it by heating razor bladesa variation
I like this better. Small cut. Depth controlled. High risk for finger loss. He stepped on the cord. Yep, that will definitely be my choice...