I've discovered what I believe to be a new method. I will call it the "Kuraki" method. It's not for advanced hamon polishers. Only a beginner should use this method. Someone more experienced and set in their ways will be afraid to attempt it, but someone new with no experience will be able to go all in. It's very simple:
1- covered pan full of vinegar and dishsoap
2- set stove top to "6" (it doesn't matter how hot your stove gets, all that matters is that it's set on 6, if you don't have a setting "6" then you cannot use this method)
3- place knife in the pan and cover
4- Go watch the Super Bowl and forget all about it.
5- Realize what you've done after it's etched so far it feels like a topographical map and is severely pitted
6- Resand from 500 grit to 1200 grit
7- Be too disgusted with yourself to etch again and just polish it and put the damn handles on.
I'll post pics tonight after finish sanding the handles.