Has anyone ever started a job and walked away at some point? I'm talking the bigger jobs. I was given a four story mansion to clean that had scaffolding up so it could get painted and they wanted the windows cleaned after while the scaffolding was up. It was basically a builders clean but with over 500 panes of glass but it hadn't been cleaned in probably 20 years and it was old glass probably over a 100 years old. I put my price in and they were happy but then I started the first day and realised it was impossible to clean. No matter what I did I couldnt get it clean in the time frame they wanted so I had to walk away. I feel gutted that I've had to do it. Was that a bad business move for walking away and has anyone else done the same? Also does anyone have any tips on how to clean old glass with dirt basically ingrained into the glass that even a paint scrapper won't get off?