The rust eraser is easy to use for removing rust or other stubborn stains from knives: Wet the rust eraser with water before using. Identify the direction of the "grain" of the knife steel (you will see lines in the knife steel) and following the grain, gently rub back and forth until the rust or stain is gone. Always rinse and fully dry your knife after use.
NOTE: rubbing too hard or too long may weaken the steel and may lead to the development of more rust. Use the rust eraser gently and only where needed.