Re conditioning aluminum heads

[CA Victoria]

I couldn’t find a thread to address the repair of corroded passage ways in aluminum heads. My concern is where the corrosion has reached the fire ring area in a couple of places. My MIG welder is not set up for aluminum so I will have the work done by a competent welder. Albeit not rare heads they are from the 50s and I want to save them. This is my first adventure with aluminum heads so I wanted to reach out to y’all for advice on repairing these areas and the correct installation. Any idea what works best to soak the water jackets in to remove the scale?
Advice thus far gleaned from other threads on installing aluminum heads is to use composite gaskets and an anode.
Your thoughts.......
Thanks in advance!