I honestly don't remember specifics off the top of my head, but I can give you a little info! I don't think you can use your Magic Band. I think you can use coins or a credit card. I'm sorry I don't remember that well... I'm usually trying to hurry up with the laundry so that I can swim! One cool thing to check out, though:
http://classic.laundryview.com/disneyworld/. This told us when the laundry machines were open so that we didn't waste our time hauling all of the items from our room. One tip: Use a suitcase for darks and another for lights, and roll 'em down! Easy peasy.