Ron, as a newbie to BH and cleaning channels, I guess can see why folks would suggest to do it by hand vs. drill. Just as a precaution so to be careful you aren't taking metal by accident vs carbon only.
Just cleaning mine after shooting for the first time the other day, I started with 1/8" bit, and after a couple twists was able to jump to the 5/32" bit and cleaned it all out pretty easily, by hand. That is my rookie .02 fwiw.