I like the AcousTech Big Brush. I find the conventional carbon fiber brushes too stiff.
https://www.needledoctor.com/AcousTech-Big-Brush?_vsrefdom=adwords&gclid=EAIaIQobChMIi_Pa3qH93gI...
https://www.needledoctor.com/AcousTech-Big-Brush?_vsrefdom=adwords&gclid=EAIaIQobChMIi_Pa3qH93gI...