Well I finally found a use for those wooden grill scrapers. I have found it does a decent job on the Q's cast iron grates. It is useless on my heavy stainless grates but brush bristles are not an issue on that type of grate
The one I use has burned in perfect squares for GrillGrates so I can see how it would also work on the flat tops of Q cast iron if you are a little patient at the outset. Once they “fit” themselves to a grate they are really easy to use.