yes and get them to sheet the floor, and furniture and tv's.
when i do them i just use a normal pole with aplicator and blade it, keep the aplicator as dry as you can get away with, i was surprised how black the water was, and it will drip on you! the customers have all been non smokers. i dont step foot in smokers houses.
then just put your scrim/microfibre on the end of your pole and wipe round.
WARNING: IT IS VERY TIME CONSUMING, MAKE SURE YOU PRICE IT WELL
the next time i do one i'm going to use a Wagtail, it will make the corners and the angles easier.
also if the roof is slightly frosted/corrugated like some are you can get away with straight pulls and not worrying too much about the lines, but however if its clear glass like the windows your gonna have to do a mint job, cos for the next few days thats all they'll be looking at.