All the years I've been doing CCU many contractors like to blame everything on the cleaners they broke this scratched that and so on. Dont let them try to cheat you write down everthing you find wrong with the project broken caninets scratched windows and so on. I wont touch a window that has not been preped right until the project superviser has seen it and I make him sign a glass wavier before I clean it or I will have him hire a scratch removal company to to the work plus to have a list of broken items it keeps you out of court. Plus the contractor can get those things fix before the new owner moves in wich makes you look good. I have many contractors I follow around on all there projects because we do this final inspection it save them time and money and gets us the jobs.