I would not hang it. Wash it in mild soap in the bathtub, very gently. And I would roll it up and get as much water as possible out and then, if you have the space, lie it flat outdoors to dry, on a clean sheet or something similar. With the weight of the water, there's a whole lot of weight hanging on very old fabric. I have some shelving in my garage that I have actually laid on its side on the driveway (2 of them, covered with a sheet and then put a quilt to dry over it, because it supported the quilt, but also let the air move under as well as on top.