If your going to buy a vikan brush buy the square red and green one with the ordinary bristles they come with,the other square ones are rubbish and like you say Joe they leave spots on the glass,everyone i know that has used that mono square vikan has had problems with spotting.The new green one is the same as the ordinary vikan ie flocked,but like Mac say`s it needs re jetting,dead give away that it`s not made for WC`s is the place where it`s jetted.