Under normal circumstances, one would soak the blade in oil or DW-40 and then use steel wool.
However, areas of active rust go well beyond Koft areas, and steel wool would remove everything. Moreover, there seems to be rust underneath the koft. Softening of dissolving rust would dislodge it as well.
Soaking and steelwooling distally of Koft might be the main option. Gentle oiling and toothpicking the rust within the Koft area may be the max you can do.
Steelwooling will remove wootz pattern as well, and you will have to re-etch.
Hope that my suggestion is an unnecessarily pessimistic one and other people here have aces up their sleeves which they are willing to share.
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