He based his currency on Ithaca Hours, which is an interest-free local currency circulating in Ithaca, New York since 1991.
He mentioned that he was inspired by George Whitehurst-Berry’s show, Crash! Are You Ready?, after being a former goldbug.
Not only are these interest-free local currencies sound currencies, but they are also constitutional currencies. For more on why, see my article, Congress’ exclusive power to coin money doesn’t prevent private individuals from coining currency.