a couple of weeks ago I watched a video from Missouri Quilt Co. and Jenny was on with her daughter Hillary for [h=1]Beginner Free Motion Quilting (Machine Quilting) [/h]Hillary uses basting spray and said she has gotten it on her carpets and doesn't have a problem with it. So maybe you can use basting spray with your quilts on the floor. Watch the video to hear the complete conversation.
This gave me hope as I don't have a garage, and no place I could use in the basement to spray.