In no way to I proclaim to be the SME on cleaning or polishing but this is how I did it. Others might have better methods and hopefully they gladly share below.
I started with a diluted mixture of water and SuperClean
This stuff is very abrasive and will scratch (etch) anything shiny so beware. If you’ve never heard of it or used it then know it is VERY strong and concentrated. You don’t need much. The squirt bottle in the picture is 32oz. I used slightly less than a third SC to water.
Better shot in the sun.
When the pipe is clean and dry grab yourself some Mothers Mag & Aluminum Polish. I’ve used this stuff for over 10 years and it never fails to amaze me.
If you have a Dremel tool with a polisher then grab it. Otherwise don’t be afraid to use a soft buffing pad with some elbow grease…LIKE A MAN.
Small, firm circles.
Just like waxing your vehicle/girlfriend you don’t want to stay in one place too long. Wax on, wipe off, move on.