Not bad, but if you are going to do more than a few, you don't want a reamer--you want one of these:
You can get them from lots of places, some with free shipping--this is just an example.
In the machine shop, this thing was always in my apron pocket--I used it all the time. Some old timers used a knife, but the knife was triangular (like a saw file with the teeth ground off).
For small holes, these are handy: