Dried out roots are dead roots and they cannot be brought back to life. But plants shipped bare root are a different subject. Those should arrive in good condition provided the shipment does not go thru an area with high temps and provided they got enough moisture before being shipped, which is why I sometimes order with a delivery date in the Fall after April.
I would contact the shipper for instructions. What to do next depends on their policies. In the meantime, you can dump them in water for 1/2 hr to 1 hr and then transplant them into a pot until they recover and start growing again. Being in a pot, you will be able to move the pot easily if gets too sunny, woo windy, too dry etc. I would place it where it is not windy and where it gets bright shade. Water the pot until you see water coming from the bottom, stop and water again. Then the next step will depend on the shipper's instructions. Liquid seaweed is a foliar feed so you can spray it on the leaves or water the leaves to provide them with some nutrients (I do this in the early morning hours though).
By the way, if the leaves are green, I would think the roots are not dead (yet).