Do you have one? It says steel and nylon, I'm assuming they are coated with nylon?
I've been leary of trying these. I've noticed in quite a few pistol owners manual it says not to switch directions mid way through while bore cleaning with a metal brush because you could damage the rifling. I honestly don't see how you could, but what do I know lol. Anyway, I've just erred on the side of caution.