how to clean road grime off rims??

hey guys, just wondering what techniques and products can be used for road grim, tar, rubber, sap, gravel and all other weird and wonderfull black stuff that ruins our rims
trying to clean some rims up at the moment and the handy degreaser, metal polish nor concerntrated car wash detergant wont bring them back to a clean finish.
any ideas and help is greatly appreciated and im sure others might be interested in this too.
thanks guys

trying to clean some rims up at the moment and the handy degreaser, metal polish nor concerntrated car wash detergant wont bring them back to a clean finish.
any ideas and help is greatly appreciated and im sure others might be interested in this too.
thanks guys
