You might try misting them. I do this on a quilt when I have to rip out the quilting stitches and move them to another area. The quilt will eventually get washed so I know the holes with shrink but if I'm doing someone else's quilt I'd rather they didn't know I had to move the pattern. This has worked great for me. I also mist when I need to shrink fullness out of an area while its on the frame.