I believe that a Belgian blue produces a same result of 6000 to 9000 artificial stones, depending of the use of slurry or water only.

But 6 strokes are insuficient for this type of hone
My oppinion is to try begining with 30-50 with slurry and finish with 30 -40 with water only. If needed increase the number of passes with slurry and
keep the finishing strokes with water only to 30-40