My folks had a hand woven, wool, Navaho rug that was full of smoke from all the fires. I made a warm/hot bathtub with woolite. Just laid the rug in the tub and swished it back and forth several times. I left it to soak for about 5 hours. Then a series of rinse tubs, but never agitating it. Turned out great. Colors became vibrant and there was no distortion of the shape.
I realize a that your have quilts which are much larger, but it could work. Be careful not to distort while wet.
Marcia