I'll go on record to say I do not use steel-wools (of any "grade") on SS and Chrome exhaust system components.
Let me add that I also do not use steel-wool to clean auto-glass or any other automotive bright work.
IMHO:
-Why use a material that starts out being "OEM"-oily;
-That's going to leave behind very, very small shards of metal that's no longer protected by its factory oil---Metal shards: with some that's now going to find their way into the smallest of crevices and pores to begin the rusting cycle, with some becoming air-borne to settle on other areas of the vehicle (possibly being captured later on in buffing pads/microfiber towels, for example);
-And lastly: Leaving it's tell-tell scratching patterns...
Again (just to clarify):
I don't use steel-wools around vehicles!
Bob