Wondering should I use steel wool for cleaning my soldering iron tip. Is it bad? Will it impact my tip? Will it clean the black oxidization off?
Steel is typically a harder metal than the plating on soldering iron tips. So while coarse steel wool might clean a tip, it would also quickly destroy the plating, thus it should only be used "in an emergency" or with a cheap tip you are willing to soon replace.
The metal sponges arguably appropriate are made of softer materials, such as brass. And they really should be brass all the way through, not some sort of copper plating on a steel core, as you might source at the dollar/kitchen store.
But even with a soft material, abrasion counts - something like a cellulose sponge will also eventually wear a tip. And so will sitting hot with solder and flux on it.
Tips are wear items. The less they are "cleaned" and the less time they sit hot, the longer they last. But cleaning is of course necessary, especially for modern fine pitch soldering.
The most modern professional solder stations have high power heaters and very tight control loops, so they can quickly go into a reduced temperature tip-saving mode when idle, and heat right back up again in the time the operator picks up the iron from the stand and applies to the work.