What are you guys using to clean your cast iron grill grates now that wire brushes are being phased out?

Went to Walmart and Home Depot yesterday and noticed the grilling sections no longer have any wire brushes. (California, not sure if its nationwide). Probably due to all the wire brush lawsuits.

They have been replaced with nylon brushes and chainmail spiral brushes which probably wont do much to remove heavy carbonized buildup.

Just curious what everyone is doing now to clean their grates?