This video is an example how NOT to clean solar panels. As I watch this video, I cant help but get distracted thinking about all the microfractures being created in the cells. The pressure and deformation of the panel will lead to premature failure. The synthetic fabrics and used in bathingsuits are not recommended for scrubbing PV modules. A horsehair brush is the best type of brush for cleaning modules, since the frayed ends of the hairs multiplies the cleaning edges. It appears standard tap water is used, rather than de-ionized water which acts like a magnet to attract the dirt and carry it away. To decrease the labor expense, a 3 person crew should spread out and wash modules systematically, rather than everyone washing a random panel at the same time.