i use a dish washing brush from wilkos lol, its perfect to get in the tight spots and its not to harsh so it doesnt scratch. majority of my brake dust comes off with the pressure washer once its gone just keep on top of it and it should come off fairly easy. ive always been told to sty away form alloy wheel cleaners as they can do more harm than good.
heard wonderwheels was a good one as it didnt have much acid in it. cant say ive used it much tho.