A sandblasting nozzle allows one to use sand propelled at high speeds as an effective and very efficient tool in cleaning. Sandblasting allows you to easily blast away unwanted elements such as paint and rust. Why use a sandblasting nozzle when there are other methods of removing such unwanted elements?
The answer is simple. Sandblasting makes what would otherwise be a difficult and time-consuming task fairly quick and painless. Instead of scraping away at the unwanted paint or rust and, possibly, using harsh chemicals in an attempt at removal, you can safely and effectively just blast it away. It is a simple way of accomplishing what would otherwise not be a simple task.