Oscar,
I cleaned my Sierra parts by electrolyse a few months ago. Watching at your pictures, I just noticed the position of the electrode. From what I've read everywhere, current circulation is better if the electrode does not touch the walls and the bottom of the bucket. It is also better if you can make an electrode in a "cage" shape, surrounding the part to clean, cleaning will be more even (electrolyse is also function of the distance between the anode and the cathode)
Just thoughts.
If you want more details, you can read
this page of my blog (forgive my English) about that: I didn't come back on the electrolyse process that everyone knows, it would have been useless, but thanks to a lot of informations I gathered on Internet, I tried to describe what to think about to make it efficient, and what to avoid to keep it safe.
Hope that can help.
Good luck for the messy job (because it is
)