I wouldn't use sashing for those mini-granny squares if they were set on point. On point, they have lines running through them diagonally and end up looking like a sort of argyle pattern. I wouldn't disrupt that with sashing. I love those little blocks and will have to use that idea for something... maybe a baby quilt or table topper.
Sorry you didn't find the fabric you were looking for, Donna. You'll just have to go to another shop... shucks. (JK!)