I have never personally experienced major corrosion on the traces of a circuit board. Or do not remember a pronounced case of it anyways. I suspect a soldering paste heated a little with a soldering gun might remove any copper oxide. After all its function is to clean the copper to promote solder adhesion normally. Never use acid type paste. Still this should be taken with a grain of salt. Others may have better ideals. Then there is the problem of removing any residue from the board after the proccedure. This part should be manageable.

The far more common problem was surface conduction through contamination. Sometimes hard to find initially on electronic boards. An alchol bath was recommended if caught early enough. Sometimes the board itself would develop leakage or resistance through the earlier phenetic type of material. I used to drill out the area where possible and jumper the area. This whole area was always questionable as there might be other areas of the board just starting to conduct as well.

I assumed this effect was caused by contaminated board material used in manufactuing. Or heat and aging made the board conductive. You might be better if the corrosion is really advanced to check out a junk yard unit. If those traces have major corrosion one could be open for example either before or after the corrosion removal.

At the least in severe corrosion cases I would suspect you might have to rebuild the copper traces with solder. Wait awhile as certain people on site do marine electronics and might have good suggestions. I am thinking people like Yellit who service marine radar units in the gulf area of the southern united states. The operational salt climate there has to be rough on units. You might want to drop him a note as I do not know how often he is on site. Good helpful guy if any possible solution is practical in my mind.