The key is looking for the smallest, most minute step toward the behavior you want. For horses it's often as slight as shifting weight in the right direction. For more info, I suggest the book "Don't Shoot the Dog" or googling "shaping."
For the same reason Remi goes nuts when I get out the prong collar (it means OB training, which he loves), he'll start to associate the tool with reward- and a jackpot size reward if he really gets it.
For my cattle dog the jackpot was jerky. I'd go to the gas station and when he saw the beef stick, he knew it was nail time, but that he would get the jerky when we were done. He always has been smarter than the lab though
ADD: the flip side of this is not to move faster than he allows or you'll throw it all away. If he lets you pet him with the dremel on today, but he didn't yesterday, call it quits and go further tomorrow, or the next day. It sounds like you may be going a bit fast.