I belong to a charity quilt group and they use this method to tie the quilts.
The woman who showed me how to do the tie said she saw it on the internet but I have not been able to find it.
At yesterday's meeting, she and I looked together for Horse Tie Quilting but did not find it. She doesn't use the internet searches much.
They donate to veterans, shelters, children's hospitals etc.
The method is a running stitch, go through w needle and string (or yarn, or crochet cotton thread) all layers of quilt twice, then flip the string up and go through the opening, flip string down and go through opening, repeat.
The method reminds me a bit of macrame. Maybe I should be looking for a macrame tutorial..... It results in a simple square knot.