How to clean a rag rug

Found this in a book I re-discovered in one of my bookcases, by the wonderful Lillian Beckwith, on how to go about restoring rag rugs to their former glory:


"Doormats which had been caked with winter mud had been beaten and were now lying well wighted down with boulders in the burn. Upstream of the doormats lay the hearth and bedroom rugs, similarly weighted, and there I intended they should stay until the swift-flowing water had restored the doormats to their normal ginger-brown shagginess and the hearth and bedroom rugs looked as if they had just come back from the cleaners."

Wonderful.