This method should apply for Bronze in no way, because they will attack the material and permanent damage. Polishing microfibre also brings little. So I consulted the Internet, and I eventually ended up with "Nevr-Dull". The price here on Amazon compared to other stores quite low, so I once ordered a can.
And what can I say ... I'm excited! This cotton and bronze shines after a little Rubbelei again. I scratch the jewelery first with a little NEVR Dull from, and then put him in the ultrasonic cleaner. That's not necessary, rinse under running water does it well, but the ultrasonic cleaner is just in every crevice. In any case you should make the rinse immediately after treatment with the cotton, otherwise creates a white layer on the metal. After that polish with a microfiber cloth, and everything shines again. I've tried the cotton with a totally black tarnished silver spoon. It was really amazing how effortlessly with minimal effort the shiny silver came immediately to the fore.
All in all I can recommend the cotton unreservedly - especially for metals that would otherwise not so easy to polish and to clean. Even my Hartzinnringe I can therefore polish up a little.
Cotton wool smells quite incidentally after car repair shop, and you get them even oily fingers - this is of course absolutely no downside, but I want it mentioned only once.