It's simple, it's inexpensive, and it's an example of how sometimes a "simple and inexpensive" design can be just what is called for. With a shank of twisted wire, this brush will bend as needed to follow through a draft hole, with a loop at its base, it's easy to extract, and with the fine, stiff nylon bristles arranged in a corkscrew pattern, turning it in place will allow the brush to work its way through even the most stubborn build-up.
These brushes don't have rubber tips like some of the other ones I have bought. If the bare metal brush tips keep hitting the inside of the bowl, over time a pit will occur and it can create a hot spot that will lead to a burn out.