I do this a bunch at home, my setup has also migrated to work. Simple solution made with vinegar, salt and sodium laurel sulphate, then a couple of cheap nickel electrodes. Run current through both to make the nickel acetate, then you're good to go.

Would using Nickel plated copper wire help prevent galvanic corrosion of carbon steel when grounding a fence using copper wire? Or would the copper coated with Nickel still act as a cathode making the fence anode??

I like the idea of adding extra anode wires to within cavities to get better coverage that this document suggests.

My favorite type of nickel plating for home scale is nickel acetate. It can be as simple as a 6v lantern battery, a nickel guitar string, and some vinegar (though guitar wires make terrible electroplating electrodes since they break and fall (something this document says can be mitigating by using a titanium basket)).