test one of each....soak in warm water, and if it bleeds, you can hand wash them with RETAYNE. I wash jelly rolls and charms all the time...so what if they shrink 1/4", if they all shrink, then they are still going to match up!
I use a salad spinner to spin them nearly dry and then iron them with NO steam...rarely do that shrink enough to make a difference. BUT, since all the fabrics are washed, then my blocks do match up! If the pattern says your blocks should be 8.5" and yours are 8.25" what is the big deal....as long as all of your parts are the same size, your blocks will all be the same size!
batiks rarely bleed...unless they are the cheap ones from JoAnns and Hancocks as they are mostly painted and from Indonesia....
give them a test, I bet they are fine!