Originally Posted by
Peckish
I found the fastest and easiest way FOR ME was to use a box knife type of blade and, working from the back, pull the backing away from the batting to expose the threads, and just touch the thread. When the blade is sharp, the threads just melt away. The blade doesn't get anywhere near the top, and I've never had any accidents. It goes pretty fast. I frogged a queen size quilt in one afternoon. The down side is you end up with a thousand tiny pieces of thread all over the top. I usually use a lint roller, which works great.
This is what I usually do whenever I need to take out a long line of stitches whether pieced or quilted only I do use the smallest rotary cutter as tessagin mentioned. And as Peggi said, whatever you use it needs to be sharp because you do only just touch the stitch to cut it and then pull the fabric gently away so a few more stitches come out on their own. Sorry you have to do this but if you love the quilt top you made, you will be glad you did. And yes, talk gently to you LA'er so she knows what happened.