I use warm and natural batting and fleece as the backing for all of our bed quilts. I just throw them in the washing machine with my regular detergent, and I never prewash my material. I have never had a problem and I have done at least 20 quilts this way. And I only use liquid detergent, I have a front loader, and never have a problem with odors staying. I do have to add that I only hand quilt my quilts. I have never tried them on the machine, so I dont know how that would go. But some of them have been envelope style so I have been sewing the batting, top and fleece thru the machine and it went thru ok, just thick.