Umm, point out to me where I ever mentioned anything about "black sludge"? It's orange sludge, and I had to dig it out of the coolant ports on both heads on every 3800 car I've pulled a LIM off of. Lots of chunky orange goodness from the rad ofc, never pulled the end tanks off to see what it looked like inside there, though. The Dex isn't any better for aluminum, so I don't know where you're getting that info from, my regals lim was pitted to hell around the coolant ports, would've taken pics but it's already pretty well documented.
Idgaf what anyone does either, like I said, they can read the info, Google search images of dexcool, and make their own decision. Manufacturers also don't care what's best for the car, so don't let that be your guide, they're out to make money. If it outlasts the warranty period, they could give a **** less what happens afterward.
