A pipe cleaner, otherwise referred to as a chenille stem, is a type of brush originally intended for removing moisture and residue from smoking pipes. They can also be used for any application that calls for cleaning out small bores or tight places. Special pipe cleaners are manufactured specifically for cleaning out medical apparatus and for engineering applications.
Outside of their originally intended purpose, they are commonly used in crafts, and are also popular for winding around bottle necks to catch drips, bundling things together, as a twist tie, colour-coding, and as a makeshift brush for applying paints, oils, solvents, greases, and similar substances.
