There used to be an available product called Wesley's Clear Magic. It was cold water activated and brilliant at cleaning anything I threw it at. Some plumbers installing fire pipes in an office building had rubbed mass amounts of black pipe grease all over newly installed white fabric wallcoverings, and Wesleys took it right out! Naturally i proceeded to try it on my vehicles (and red dog vomit stain on an expensive bedspread), and it never let me down. Biodragable like simple green, 50 times better, but i've not seen it for 15 years, at least. Hot water deactivates it, btw.
I try simple green every 2 years, have never been but mildly amused by it. No matter what i choose to clean with it, there is always a better product available. But i give the marketing gurus credit, for suckering me again. As was stated by Pacific Coast Datsun, it is awesome for dirty things, like bottom of the hood, and safer on paint than many more efficient choices. But for grease, like what is again embedded in my knuckles and pores, Gunk Engine Brite rocks. I have just tried my first of many cans of the newer foamy stuff, its pricey, but most impressive. Then again, kerosene or paint thinner are cheap and quite effective too. I know several pros that only clean with gasoline, and naturally, their all heavy smokers to boot. go figure