Below is a list of Bottle Brushes manufacturers from Denver, Colorado. Also called flue brushes, bottle brushes are a type of brush in which the bristles radiate from a central stem and are most commonly used for cleaning hard to reach areas in bottles. Designed for strength and long term use, bottle brushes can also be used to clean holes after drilling; they can also be used to clean air and water purification systems as well as the interior surfaces of test tubes. Test tube brushes differ slightly from typical bottle brushes in that they offer tufted ends that provide effective cleaning of test tube bottoms.