I gotta say - if you use a wire brush to clean your grill, and there is enough gunk still on your grill to hide a brass bristle - your grill isn't clean.
Leave the grill hot - right through dinner. Burn off most of what is stuck to the grates, then a light brushing dusts off the carbon. No need to throw out wire brushes (though the wood paddle had no real downsides either).
A bristle could easily get stuck on the side of a bar that you can’t see.
1700 ER visits probably isn’t that high in relation to the number of times people grill, but why risk it? Seems like an absolute hellish thing to go through.