Great idea! I like the idea of using the batting square in place of foundation paper. Great for log cabins and string quilts
If you put a backing square at the back, you will have a reversible quilt!
The sashing part is a little troublesome though.
I will try this one day when I have enough mental strength of handle my scraps.
(Edited to add: Oh yes, saw the youtube tutorial on joining blocks without sashing. Cool!)