Recent article on greasy airplane
Never us Purple Stuff or most water based degreasers found in the big box stores as suggested in article as it is extremely caustic and corrosive to aluminum. I actually owned a chemical company by accident years ago and we made a similar product and one of the main active ingredients is caustic soda. It will also do a good job of defatting your skin. Ok to clean a lawn mower or a tractor but never an airplane. Simple Green makes a specific airplane degreaser which is pretty much ph neutral and non corrosive. I use avgas on shop rags and finish with it and a rinse with lots of water