The pipe-cleaning brush is inserted into the tube to be cleaned and moved in and out.
Using a brush slightly greater in diameter than the tube to be cleaned allows the tips of the bristles to rub against the inside of the tube.
If you are using an abrasive pipe-cleaning brush to prepare metal for soldering, the bristles scratch the surface creating tiny grooves which the solder can attach to and create a strong join.
If you are cleaning a pipe or fitting, the bristles dislodge the sediment and the movement of the brush sweeps it out of the tube.
