I've used wash away water soluble embroidery stabilizer on a smaller crib size quilt. More expensive than dryer sheets, but worked fine.
Like this:
https://duckduckgo.com/?q=water+solu...-1&ia=shopping
Like you, I've used dryer sheets, muslin and I also tried fmq paper (thin paper like newsprint), and tissue paper. I really liked the ease of just washing it away...not tearing and picking or leaving it in like with muslin. But you have to be able to wash your project.