Just one little point ...
I do my own copper and nickel plating, aluminium and brass etching as well as stripping chrome from parts prior to replating so I have a little experience in transporting metals electrolytically from one item into solution, or onto another item. Although if I have been doing it wrongly for the last 30 years, please feel free to point me in the correct direction.
Metal is dissolved into solution FROM the anode "positive" and deposited ONTO the cathode "negative". So if you attach your file to the cathode "negative" electrolytic transfer into the solution won't work.
As I mentioned before, different metals are dissolved by different solvents and while aluminium is very soluable (without electricity) in a caustic (alkaline) solution, cupric, and ferrous metals do not respond the in same way.
To remove copper alloys electrolytically you can use copper sulphate as an electrolyte, and a steel, or copper washer attached to the cathode "negative" with the anode "positive" attached to your file. This will cause no damage to the file as ferrous metals are insoluable by copper sulphate, but the copper alloy clogging it will be dissolved into the electrolyte and excess copper from the electrolyte will be deposited onto the cathode.
Soda baths won't dissolve, or erode cupric, or ferrous metals, which is a good idea as the finest (sharpest) edges are the first things to disappear when chemical erosion occurs. It can "seem" as though a little erosion actually helps, but this effect is predominantly due to the fact that the offending aluminium alloy has been removed. (Try dropping a small drill in acid overnight and see how blunt the edges are in the morning)