The light green stuff will have to be manually removed. If it is bd, it will be easily scraped off using a strait pin, exacto, etc. I have yet to find anything that actually "eats"
bronze disease (ie, you could soak it for a million years without manual cleaning and it will
still be green and easily reactivated).
The stuff circled in black is what you need to concentrate on. That is where the bd is eating in to the coin. All of those pits will have to be cleaned out. The upper stuff (circled in white) is an old and non-active looking bloom (the green on top of the reddish chalky feeling stuff). You could reduce that down to the
flan level, but the
red will be IN the
flan, so if you decide to reduce it, make sure you stop at
flan level otherwise you will have a divot in your coin after finished.
Chris
Edit: The way to do it is: manually clean, soak overnight, manually clean, soak overnight, repeat until all the pits are cleaned out (changing the bd soak water every other day or so), then let it sit out in your normal enviorment for a month or so to see if anything reactivates. If not, call it done, if so, repeat as needed.
C.