My dogs gave it a quick funny look but I didn't put up with anything and they both 'like' it more than nail clipping.
For black nail, take a little bit off at a time, when you are getting close to the quick you will see white with a black circle in the middle and you will want to stop there.
Dremels are very easy to use. use the low setting if you put it to the nail and it skips turn the dremel around (so instead of point right point it left) and it will go smoothly other than than it's piece of cake. Just watch if your dog has long hair to hold it back away from the dremel. I have caught my dog's hair in it once and it wasn't strong enough to pull hair out or anything it just stopped the dremel but just be careful.