Originally Posted by auntmag
Try hand washing in cold water and mild detergent. Dry on low heat in your dryer and it should straighten a lot.
Wash it it in hot water and a hot dryer .... that way you know the worse case scenario. And then decide if it's worth trying to rehabilitate it, or if it's better to chalk it up to experience and say ...... NEXT!!!
Before "blocking" it .... have someone help you and gently tug on the opposite corners to help stretch it towards square. Then do your blocking process and let dry. I'd pin it to a carpet or something fabric, to help with the moisture. Not the a bare floor!