I had some vintage blocks that I didn't want to bother quilting if I couldn't get the stains out. So I pieced together, ran a seam of stitches around the outside edge, then SOAKed in either RetroClean or Restoration (have used both successfully with older quilts/linen) in my top load washer tub. Spun out the water once soaking done (when hot water cooled), did it again a 2nd time, and then quilted. Worked great and these all had white backgrounds.