I've made raggy quilts for a few years now. I have used all different size squares; including 5" squares. However, my favorite size is now 8.5"; I lose less fabric with this size square. Also, I also clip a few rows at a time. I have arthritis sp? and if my DD doesn't have time to clip for me, I can only clip a little at a time. Good luck! And if you need extra help, just PM me.
As a sidenote, guess I've been lucky; I don't prewash and have never had a bleeding problem. Also, have never had trouble washing for 1st time in my washing machine. Of course, I do have an extra-large tub.