I don't know if it works yet. but, I found this beautiful curtain at a yard sale that is made simular to lace. I laid a piece of blue fabric underneath it and it made it show up so pretty. I thought I might try quilting it and making it into a wall hanging. You might try this. Now, something else that I've seen is starching them really heavy and placing them under glass (like in a picture frame). If the stains are bad and won't come up, Place a dried flower in that area if it is under glass. If not, then applique something over it. Hope this maybe jogged an idea loose for you.