Well, you might want to qualify "it worked". There's a reason they moved to silver.

There was a point, when taxes were still assessed in rice, that the relevant official announced a large tax increase because the government just wasn't able to operate on what it was getting from existing taxes. He also started the process of reforming tax delivery, largely by making sure tax barges could make their way down the river without excessive delays. They had been arriving nearly (or completely!) empty thanks to predation by vermin.

The delivery reform was so successful that the tax increase was canceled. There were no (significantly problematic) issues with taxes not getting paid; expenditures were well within tax revenues; but... using rice as a currency meant that just because somebody paid you money didn't mean you actually received any.

There's a big difference between an economy and a currency.

Giving people money isn't giving them an economy either, it's giving them currency. The economy comes when they trade, it doesn't really matter if it's dollars, gold, rice, or bitcoin, people just have to agree on it's value.