AW Perkins 32 Inch Fiberglass Rod with 3/8 Inch Pipe Thread

I need a four-foot or similar section of very flexible chimney cleaning rod with a 3/8 male pipe thread to go around a bend at the bottom of my 6-inch metal chimney flue. I currently have yellow Schaefer four-foot cleaning rods, but they are quite stiff. This would allow me to clean the flue from the access port at the bottom of the metal chimney pipe. Do you carry such a product? Thanks.