Ok mate.Not now but I did at first. I had to explain to most of them to give it a chance it will improve with every clean and after the third or fourth clean it will leave them spotless. But i also said after that that they will have all their frames and sills cleaned aswell as part of the process of cleaning them. So the majority were happy with that as they was more for their money.One or two didnt like me leaving them wet but i said its part of the process not touch them after you clean them as you run the risk of leaving streaks. One or two persistant ones asked me to blade it off so i said i will compromise and blade the downstair off.