I wouldn't soak a quilt for 24 hours, as I don't like potentially bleeding fabric touching other fabric for that long while wet. If you let some washable glue dry on your hand, you can pretty well tell how easily it will wash out by rubbing it under some water. White water-soluble glue dissolves in water; I honestly don't understand why it would need soaking, especially not for 24 hours.
Edit: I'm not seeing a link to the Elmer's site mentioned by frannella. I have a bottle of Elmer's washable school glue here, and on the back it says "TO WASH: Pre-soak 10 minutes in cold water. Follow garment maker washing instructions." Ingredients are not specified, but my understanding is that this glue is simply starch.
Last edited by Prism99; 02-18-2012 at 10:52 PM.