There are plenty of posts (and answers!) on mold removal, but not on what constitutes "clean".
I've scrubbed the walls down with Chlorox and a striff bristle brush. Gone over it several times. The walls are cement block, painted white. The paint has held up well, no flaking. The appearance of the blocks has improved, but there are still a brownish/ blackish stains on the blocks, especially in and around the mortar lines. Do I need to keep scrubbing it until it's ALL gone, or is that overkill? Would a wire brush help?