I can only share what I've tried, new steel and old steel react differently as well as from head to head and even given the texture of the surface.
But here are a couple of more low tech approaches/tips you could try:
First:
1. mix up a cap of white vinegar with dijon mustard - it's what I had but there are seeds that stick so maybe something like French's. Mix it to not quite a "paste"
2. cut up some dabbing sized sponges. (you won't want to save these after a couple of runs)
3. apply with dabs evenly and very thinly across the metal
4. Let that side dry completely
5. repeat other side or poll or whatever
6. wipe it clean and repeat
Second:
1. run a looped wire through the eye so you can hang it bit down.
2. coat the edge with a couple of coats of nail polish
3. put white vinegar in a spray bottle
4. mist each side evenly
5. hang outside
I think after the vinegar dries it kind of halts the darker look so you can reapply and let it dry as much as you want. Some of it will wipe off but that is when you go at it again. You can also conservatively combine all of the other ideas too.
Why not have some fun? And besides, if you don't? you are going to wonder what happens if you did, right?
Hickorynsteel - you're not a hipster.
Yuck, I can taste it now lol.
