I'm using a brush like tool on a drill to get most of the crap off.

I'm not going to need to seal it with anything since I like the look of brushed stainless turning orange.

I much rather see that than a bunch of dirty and dingy plumbing surrounding my engine when it is done.

This is one of the most visible parts of the engine from behind or beside the car so its more important to clean this up than other parts of the exhaust though they will get their fair share too.