I've booked with my Disney debit many times. You don't need to register it, just use it to pay your deposit, so make sure you have $200 in there. They will usually send an email telling you about it, but you will see it here before you get the email. It's usually available to us a few days before it goes to the public, and you don't need anything but the card, because they know by the first few digit of the card number if it's a Disney one. Again don't wait for the email, keep stalking here. I was booked last year right at 7:00 am because of the tip here, but didn't get the email until the next day.