I just got through removing popcorn ceiling in one large room in my home. I purchased some heavy plastic sheeting (4mil)to cover the entire floor area. Next bring in the garden hose with a sprayer that could produce a fine mist spray,(needs to have on/off capability). I would spay an area about 6ft x 6ft and let it soak for a couple minutes this use a long handled wide scraper. The stuff just comes right off dropping to the plastic. Be careful not to gouge the drywall. When I was done I just folded all the stuff into the plastic and minimal mess is left. I did have to do a small amout of touch up topping to the dry wall after it dried. This was part of a complete room remodel so I spray textured the ceiling (one of the large hopper texture guns) and all the walls. When complete it all looks professional... This inspite of the fact that I hate drywalling!