Originally Posted by Lori S
Great find, as for washing the blocks .. I would soak in a sink or tub with water and vinegar , occasionally swishing . And lay flat to dry. You may want to roll the wet squares in a dry towel prior to laying flat ,to speed up the drying .
Do just a few as a test first.
I did exactly this with my blocks yesterday. only thing I would add is use a color catcher too since you have no way of knowing if these will run or not.