I have used pearl cotton for applique and fancy stitches, only it's used in the bobbin (I have an extra casing with the tension screw removed). First straight stitch around the edge of the applique, this gives a guide line to sew the blanket stitch or such from the back side.
AHHHH!!!! Now that is an idea!!! Hmmmmm....I think I'm going to have to try that....