In 2014, I bought a copy of String Quilt Revival by Virginia Baker & Barbara Sanders. This book was one of those "Create with Nancy" ones with a DVD included. They use a non-woven nylon mesh stabilizer as foundation, which can be ordered from Nancy's Notions or the website of the authors. A short time after that I saw a discussion on here in which someone said they use the aisle runners bought in the party supplies section at places like Wallyworld. A friend keeps urging me to use the dryer sheets, and I have saved some, but so far not sewn onto one. All my laundry supplies are unscented and dye free. I prefer the look of string quilts above all others, and haunted Mary Johnson's site "Mary Quilts.com".
After a weekend of working on blocks for the cover quilt in Baker & Sanders' book, I came to the conclusion that string quilts are not as quick and easy as I thought.
If quilts are stuffed with polyester blends and W&N has a synthetic scrim, I cannot see a problem with dryer sheets as stabilizer. Just be careful when pressing directly onto the synthetic with a very hot iron.