Ok here's the best kept secret I have. Home depot Zep orange oil. Rinse with normal hose, spray with undiluted ZEP orange oil, let it set a minute or 2, wipe with a terry cloth towel. When you rinse the bike the water will bead off due to the extremly light oil residue. Not oily to the touch and when dry won't look dried out like simple green. Spray the towel it'll come out white. Bike will keep its new look longer.
For tougher stains on an aluminium frame I use mild scotch brite pads soaked in Orange oil.