The Elmer's glue will wash out. I like to cut the center out of the fusible and just leave 1/4" or so around the edge (I believe that is the window applique you are referring to). For example, you cut a circle, then you cut 1/4 inside the circle and just fuse the ring. That way, the rest stays soft and you can quilt if you want an it won't gum up the needle so much. I also like to use Lite Steam-a-seam. That in itself is a little softer than some of them.