Originally Posted by Driz
... and mist some armor all or similar all over the plastics and rubber stuff. Just let it lay as it sits after you rum it around to get the hose bottoms of hoses. Next day it'll be shining
Yes, and 2 days later it will be covered in dust again. Armor All is a horrible thing for under the hood, just attracts more dirt. There are other sprays and such to use to make it look nice but not Armor All.
My regular routine is get cold engine wet with a water hose, spray with degreaser (been using "Purple Power" for past several years, works as well as Simple Green, but 1/2 the price), let it sit for about 10 minutes, then rinse off. Keeps the engines looking nice.
If as dirty as the OP said, it may take more than that, but sounds like they got it taken care of. I would be a little worried about all that dust almost turning into a cement like shell if it was not all washed off.