I have Evaporust in my arsenal, but it is hard to apply when working the underbody. I've tried soaking a rag and leaving it on and it's worked decently. I believe I also have a gel form and it works well too. I guess there are many ways to accomplish the things I want to do, but all involve elbow grease
How did you soak that large pipe in the Evaporust? I thinkt he rolocs works fine on something like stainless, but is a bit too rough on this aluminum piece.