it sometimes works ok. other times no matter how long you spend on them they wont be right.
my best advice is on the first clean do all the frames first removing as much of the flakes and muck as possible ,then go back cleaning just the glass and avoiding the frames, warn the customers due to the condition of their frames they may not be perfect, if on the following cleans your customers are not happy then on these jobs i would go back to using ladder, some would say get rid of the job but i am their to provide a service and sometimes the ladder is the right tool to provide the service.