@NaomiSkarzinski @ceorl @CinnamonGirlE @LnzyHou @CJLavoie
It's old school and was a primary cleaning agent up through the 50s. Apparently you can make it by baking baking soda at a certain temperature in your oven. Its a chemical conversion brought on by heat.
That said, it's easy to get off of stores like amazon, and often in the laundry aisle in your local grocery store.