Dogs are generally more comfortable having their nails dremeled than having them clipped. Dremels don't seem to pinch or squeeze the nails the way clippers do; you can get a nice smooth edge to the nail; it's much easier to avoid hitting the quick. But they do make noise and vibrate the nail as they grind it, so you have to go slow introducing one.
I pulled up this old post to give you a little intro to the process:
I use a cordless Dremel multipro--the rechargeable battery doesn't have a super long running time--if you're doing multiple dogs in a row, that could be a problem for you--but a corded dremel is rather a pain to use (for me, anyway)
Dremel style tools marketed specifically as nail grinders for pets often don't have enough power to do tough dobe nails--it's really better just to use an ordinary hobby dremel with the coarse sandpaper roll.
Thanks melbrod - my wife says we have a Dremel somewhere from when we tried to do stained glass.....I will have to find it to see if it is still in good shape.!