I am confused by this you say after using 8k norton you go to grey stone then red paste then I assume Crox being green. What is the role of the grey hone when 8k norton level is about 3 micron. The Red paste again assume dovo red which is also about 3 micron and the Crox which is .5 Micron. What is the grey hone doing between 2 similar grit progressions. I dont get it. Please explain.