You can probably guess from the name "pipe cleaners" that they are more than just a tool to do arts and crafts and that, at least at some point, they were used to clean things (probably pipes). It probably comes as no surprise then that they can also be the perfect tool to clean your sewing machine. The sewing machine has so many little nooks and crannies that can be hard to reach and a pipe cleaner can help you to reach them.
The bobbin case especially can be a very difficult piece of the machine to clean...and yet it is one of the most important to keep clean. Pipe cleaners to the rescue!