A chalkboard eraser vacuum would have fun! But, we did it the old-fashioned way.....clapping erasers was one of the end-of-day classroom tasks I performed plenty of times. We probably inhaled pounds of chalk dust by the time we finished 8th grade, lol. Pounding the erasers against the side of the building was a strict no-no, unless you wanted to incur the wrath of the principal Sister Richard Marie!