I use something similar to the .17cal brush-- a pipe cleaning brush. I cut the loop off the end of the handle, and chuck it up in my cordless drill. Works great, and since the bristles are nylon I don't have to worry about one coming off and causing a short somewhere. Link to what I'm talking about below, but I can get them for 1/4 of this price at my local smoke shop.
https://www.amazon.com/Pipe-Cleaning-Brush-Tobacco-Stainless/dp/B00BXU6E8I