Fray Check, made by Dritz works like nail polish to keep the holes from ripping further, it's a little less stiff than nail polish when it dries, and since it's made for this purpose there may be other reasons why it works.

I'd use Fray Check on the edges of the hole, and if it is small, just stitch it up by hand and then fray check the scar. If the hole is big and needs a patch, the sacrificial fabric is the way to go. I'd consider running a bead of fray check around the edges of the patch before stitching it in too.

You can tell I like the stuff, but maybe that's just because the fumes have gone to my head.