Oh yes the Super Clean will discolor aluminum also. But DAMN that stuff works great on greasy old cast iron stuff. And driveways, it works great on driveways.
What I love about it is I put the greasy thing right there on my driveway and and spray the Super Clean on it then hose it off and the driveway is CLEANER than if I hadn't cleaned that greasy thing there.
Now that works for me!