My sister made multiple poly quilts from squares they found in her MIL's stash after she passed. The backings are polycotton and they are tied in the center of each square. The quilts went to each of her MIL's great grandchildren as car blankets and many are still in use. They have been used as picnic blankets, emergency blankets for warmth, and thrown on muddy ground to protect clothing while changing a tire. They wear like iron and wash so well.
Applique over the hole-y squares (If you need some doubleknit, I'll bet the QB members could help with that!!), sew on a backing and use the 'birthing' method to finish the edges, tie in the center of each square or use the eyelet stitch on your machine. Top stitch or blanket stitch all around the edges and call it done.
And don't forget a label!