Platonic Currency: The Hour Coin

 You can immediately see the superiority by contrasting debt-backed currency with labour-backed currency. The mint would strike a coin and use it to pay for exactly one hour of labour. Likely it would inflate the currency until it was one hour of unskilled labour. If it tried to inflate it any more than that, even labourers won't agree to work for a full hour in exchange for a coin, and the mint won't be able to strike any coins.

 Result: all prices are now denominated in hours of unskilled labour. You can see at a glance how much work goes into any retail good. Further if you want e.g. help moving, there's an obvious Schelling point. You know exactly how much you owe them. Can't argue that the hour of time was worth less than an hour coin.

 Naturally this is impossible under Fascism. It also reveals exactly how much more you're worth per hour than a labourer. If you're getting paid five hours per hour...well, now you know. If you can't even get someone to agree to pay you a full hour per hour....well, now you know. Can't fudge the hierarchy.

 Since there's a natural inflation/deflation buffer, if someone forces inflation anyway, you can watch e.g. a candy bar be worth ten hours of labour. The violence becomes revealed to the intuition. Absent fraud and graft, economic growth must show up in falling prices.