The ones falling apart would need to be repaired before cleaning. Often people put tepid water in the bathtub, with Mild soap ( there are some made specifically for quilts/ textiles) or ones like dreft or woolite. Place the quilt in the water gently push down, allow to soak, can push down over the surface a few times. Drain the tub while the quilt is still in it, push down to remove as much as possible. Put clean water in to rinse, doing the same. Drain, push quilt against bottom of tub to remove water. Carefully remove the quilkt, lay it out on a clean sheet to dry, ( if outside cover with another clean sheet to protect it from sunlight & critters/ birds. When one side is close to dry turn over & let the other side dry.