Once it's at a super clean 2500---
---then I start to etch. I have found two methods that I really like. Either vinegar, or lemon juice.
This blade I did with vinegar. You cut the vinegar with about 5-7 drops of dish soap to help get a more even and consistent etch. The bowl holds that stuff, and has been microwaved for 90 seconds. Application is simply with a wadded up paper towel.... rub back and forth with it saturated in the acid for 10 minutes.
Here it is after 10 minutes, the acid has been neutralized with ammonia (Windex ). Ain't it pretty?!?!?! "No." Yea, I don't think so either...
Here's the finishing bench set up for "oxide removal"
First I go after the blade with liquid Flitz on one of those round make-up pads. (I should buy stock in those little things!)