Part of my problem is I'm not entirely sure what my exhaust tips are even made of. I attached a picture below in case someone can definitively tell. If I had to hazard a guess maybe brushed stainless steel? These are on a 2013 Lincoln MKS Ecoboost. I don't think they are chrome and they feel very substantial if that helps at all. The pic itself makes it look a little worse than it actually is, but I'm really hoping to get the charcoal marks out and make it shine.

