Hi folks, I recently set a new tile floor down in the kitchen. I put in some inserts that are squares of pieces of stone betheen the tiles. The rookie I am I didnt clean out enough of the thinset between the stones and now dont have any depth to put the grout down. I tried using my dremell (sp) with a diamond bit but that thinset is some tough stuff and it wasnt long before all I had was a nub left. Any suggestions on how to grind/clean out excess thinset?.....Thanks.