Make sure you rinse the simple green off fully. I like the original myself. Havent really noticed much difference between it and the auto stuff. Auto stuff is a bit darker and maybe a bit more pungent in smell. But do make sure you get it all off. I used it to take pitch and gum off of sawblades (soak for 1-3 hours) accidentally forgot about a saw blade for about 2 days. the simple green attacked the metal and pitted it and left corrosion spots. Its a great cleaner but get it off and protect metal parts with a lubricant. (chain oil, grease, wax, whatever) Now this is not available easily enough yet. But the last time I went to my local aerospace symposium the simple green guy was there with all the new goodies. (I always get lots of freebies ) This time I got this stuff called simple green aircraft. http://gsa.simplegreen.com/gsa_products_extreme.php. yes its expensive. I just got a small bottle of it. But unlike regular simple green its safe on composites, aluminum and painted surfaces. Now im not saying that I haven't used simple green on aluminum and what not before and had good luck but this stuff is just better designed for it.

Good luck
Sean Scott