I'm still a bit dubious about the tool being for cement work. I've done my fair share of cement work and I've never seen a rolling groover. I couldn't find a rolling groover anywhere on the internet. I've seen plenty of rolling joint rakers, but never a groover (two sided) nor edger (on sided). Besides the obvious cleaning issue with the tool you posted, there's the very problematic question of how the tool would function. The typical groovers are like sleds with curved leading and trailing ends, and they have flat bottoms so there's little worry about creating unevenness. Since concrete has aggregate and is not a uniform material a rolling groover would create a divot or hump every time it ran into an obstruction (aggregate) or soft spot. You would have a lot of unhappy customers if you finished off the nice flat work with wavy grooves/edges. Here's a link to Marshalltown's groovers: