Yeah, once those exhaust tips are neglected for such a long period of time, you get to a point of no return. OTOH, it is a specific "effort" to clean them every week during the routine car wash. There's no way to avoid that apart from not driving the car. I simply think of the exhaust tips as the "fifth" and "sixth" wheels on the car. I spritz a little wheel cleaner and come back a few mins later for agitation with the sponge. The result is pretty over the long term. I probably polish 2 or 3 times a year.
Camaro, you mention the #0000 steel wool in the video. That's my first line of attack for a salvage effort like this.
Chem Guys as a very good metal polish. That's what I've been using over the past year and get good results with it.