There are many opinions in the Quilting World about which method of washing is the best for quilts. There is no one definitive method or technique which is valid for all quilts. Quilts vary in their construction, materials used, age, and degree of use. Each one must be considered individually in determining when, how best to, and how often to wash it.
All quilts have a life history and a life cycle.
Washing a quilt inherently contributes to the progress of that life cycle. Use a quilt and it is guaranteed to get dirty. Fail to use a quilt, and the purpose of making it is defeated altogether. Today when a quilt gets soiled, most quilt makers or quilt custodians wash it either in the washing machine, or in the bathtub if it is in a more fragile condition. Soil, grease and grime attract things that are harmful to quilts or any other textiles.