i use wash away thread when i do needle turn applique.
i sew my applique pieces to interfacing with wash away thread right sides together, then i snip the interfacing and turn the applique piece out, then i iron and once i have it in the shape i like i give it a shot of steam.
the steam dissolves the wash away thread and the interfacing can be removed and all i'm left with is a beautiful needle turned piece without doing any hand stitching.