Found a fantastic degreaser/cleaner today called Autosmart G101. Not the cheapest of cleaners but brought up the back wheel on my bike lovely and effortlessly. Non caustic and am told it's safe all round. Wish I'd taken a pic before I used it. Spray it on, wash it off.
Yes, it is ace stuff and used by the BMW bike and car importers when prepping the vehicles on arrival from Germany. I have bought several of their products from the local to me franchised salesman. They operate rather like the Snap-On guys.