Those SiC coarse-grit dressing stones will only cut like something approximating 36-grit during the first use or two, when used with the typically moderate-to-light touch applied in sharpening a knife by hand. I have one of those from Norton, and it smoothes out very quickly after some light use, even after only a knife or two. It's like a lot of 'coarse' manmade stones, in that it won't retain it's original rated performance very long, if used with a moderate or light touch. If it were used as it was intended, i.e., dressing an aluminum oxide grinding wheel running under motorized power, then it'll quickly shed and refresh it's coarse grit, and I'm sure will continue to cut more aggressively. But when used by hand, it's more likely to smooth out and and even glaze a bit, until or unless some more aggressive scrubbing is done to keep it refreshing itself with 'new' coarse grit underneath the surface. This is also true of the cheap tile-rubbing stones in AlOx, if used with the moderate touch required for forming a keen edge on a knife blade. I have one of those as well, rated somewhere around 60-80 grit, and it's less aggressive than the 'finer' rated stones I have in AlOx or SiC, from Norton or ACE. In fact, I gave up on it pretty fast, because it glazed and slowed down so much after the first use or two.
So, I don't question it's a rated 36-grit stone. But instead, I seriously doubt it's still actually cutting at that level, to give the results claimed. I also believe it's a little 'gimmicky', as previously mentioned, due mainly to the fact they smooth out so fast, if the stone isn't used with sufficient pressure to keep it refreshing itself. Still, it requires a pretty good touch to get the results shown, but it's not quite as extreme as the rated grit for the stone might imply.
David
