I just took my brothers stock upper intake off the car, as I'm in the process of swapping upper intakes to the BBK plenum, and let me tell you something. I've never seen more oil residue in my life on an intake system. I'm glad I made a PCV filtration device to keep the oil out of it. However, there is still oil residue in the lower intake. Might have to use this seafoam stuff to see how it works.
This "smoking" thing sounds pretty cool. I think I might have to try this in my drive way and see what the neighbors think. It will be funny when they call up the Fire department and tell them the car is on fire. :lol.