Supposing the value of the fiat currency in one's pocket or bank account (if not confiscated) reaches zero due to rampant hyperinflation brought about by interest rate hikes on US Treasury bonds. The interest payable by the US Treasury on such bonds, for instance to China, would require a monstrous amount of excessive fiat currency printing, so much so that the value of the US Dollar would rapidly diminish to zero. China would more than likely require alternative forms of interest payments, such as barter in the form of various physical commodities. The question then remains as to what method of payment one would use to cover one's living expenses. After all, barter would entail carrying around fairly hefty physical items not exactly suited for doing one's supermarket shopping.
Clearly alternative payment methods other than worthless fiat currency would be required for small transactions in contrast to payment methods for US Treasury bond interest payments to China. One solution would be small rectangular chips of gold and silver sold in the form of chocolate bars, whereby each chip would be broken off for purposes of tendering payment for small transactions. The purchase of such gold and silver chips would be debited in value from the value of one's stock of gold and silver bullion bars and coins held in segregated vault storage outside the banking system. Should there be any change due the purchaser, the change would electronically be credited in value to the value of one's vaulted physical gold and silver stock. The value of gold and silver in the event of a currency collapse would ideally be advertised hourly by the media so that such small transactions can be facilitated by incorporating such updated value in purchase calculations.
Another alternative would be to use one's net worth excluding all liquid assets denominated in fiat currency. Hence the value in one's other hard assets (apart from precious metals) would be registered in a database and portions of such value used to conclude small transactions by charge card. This method of payment would steer clear of any rebirth of fractional reserve banking. The exact value of the portion of the hard assets, again updated on an hourly basis and announced by the media, would be used without any fictitious fractional value created such as with credit card transactions at the moment. For instance, the value of one's real estate holdings in specific areas would vary according to the supply and demand in that particular area for similar properties and the value determined on an hourly basis.
Such being the case, it would appear that there are solutions for overcoming the eventuality of worthless fiat currency which furthermore appear to be admirably efficient possibilities. Were the after-effects of a currency collapse be met with focus and planning well in advance of such an event, the transition of payment methods from fiat currency to precious metal chips and hard asset charge cards would probably be rendered smoother and more amenable to popular use.