I've used rayon embroidery thread for wallhangings. But any quilts that get a lot of use would do better with a polyester, embroidery, Isacord type. Rayon isn't colorfast in bleach and isn't as strong a fiber so it can fray and rub away. Someone made an embroidered vest that fell below her bottom and anywhere she sat or where it rubbed on things as she walked disintegrated over time: