I washed a bunch of pieces I had already cut for a mystery quilt, not because I was worried about them running -- I had washed the fabric prior to starting. I washed them because the smell of the starch I had used was driving me nuts, and I noticed how the same starch had stained white blocks gray.
Anyhow.... it was horrid trying to straighten them and iron them when they came out of the dryer. I had used delicate wash and a linen bag. I pressed and put the whole works away for a while -- UFO stash.
My point is I can understand the effort you've gone through. Let's hope it is all worth it!