we used brake clean or simple green if there is lots of grease/oil then soaking might be an option. then you may want to get some aluminum cleaner/brightner cause after you clean it it will look pretty dull but still better then grease.
there is this stuff at autozone called MAG wheel cleaner and it will clean anything. has a lot of acids in it and its made to clean those old ugly cast wheels but i used it to clean under my engine bay. just dont let it sit for just a second then rinsie it off good. i promise you wont be disappointed.
You're lucky you haven't ruined anything man, that shiite is crazy. I used to detail cars for a living and I dropped that stuff on the floor and LITERALLY ate the finish off the floor from the time it hit to the time I grabbed the hose to wash it away.
Now, I have had GREAT experience with Orange Blast. It comes in an (obviously) orange bottle and you can get it at Autozone, too. I used it to clean my 15 year old power steering pump and it made it look as close to new as you could imagine.