Vinegar (acetic acid) works differently than sodium hydroxide (NaOH), since NaOH is a base, rather than an acid. Acids will corrode the tungsten carbide over time so I chose not to pursue that. You can also use concentrated degreasers as they rely on bases to turn the greases and oils into soap to be able to remove them.
I am using a Keyence VHX-5000 digital microscope to view these. They are out of the range of consumers ($15,000+) so you’d be better off with a different setup to view them. I’ve seen folks get good results out of 10x, 15x, or 20x loupes with their smartphone taking pictures.
EDIT: I mention below that acetic acid (vinegar) should be no issue for corrosion of carbide or ZrN coatings.