Molas are usually made of cotton. So my suggestion would be to gently hand wash each block. I would put one color catcher in with the block. Cold water. Then I'd dry it by rolling in a towel and lay flat to dry. I'd probably go for a black border around each block and randomly place them into a quilt. I might try to keep a few out to place into a frame too. They are so very beautiful. What a wonderful memory treasure from your friend.