Here's another example of the Rotating Brush Tornado Nozzle at work. Of course, this is rather unusual as there is a large clump of loose, but heavy, material. See how it is pulled away by the induction effect. Normally the RB Nozzle is used to clean circular ducts which have hard-adhered, heavier deposits. The sort of thing you'll find in e.g. industrial extract systems (or Local Exhaust Ventilation)