I have made two very large quilts using dryer sheets. I saw no oily residue. But I also washed every one by themselves as I would a load of clothes. After I had the amount I needed for a quilt. I put them in a net bag and washed them in detergent and some bleach. dryed them in dryer and iron the flat. A little time consuming but I didn't mind because they made wonderful foundation.
BillsBonBon