when I first heard of this a few years ago, I threw all my brushes away. I use a well seasoned mesquite branch between the hot grates and a ball of foil, works like a champ and no issues with metal brushes.
Primo XL, Pit Barrel Cooker, Mini WSM,Lodge Hibachi
Craigslist finds Tiernan SOB, New Braunfels Black Diamond, Big Green Egg Mini
By the way, did she mention my name-just in passing?