IIRC, the law is something like; 'You must repay a debt in like kind.'
Thus, if your lender gave you Monopoly money to cover your mortgage/loan, you MUST pay them back, with interest, in Monopoly money.
I'm not 100% certain how it will work exactly, but I'm pretty sure that 'wiping out all debt' will not simply end at 'exchange notes' for gold backed somethingorsomesuch.