Yeah but 2 days isn't long enough. What I'd do is dump that water out and rinse the vinegar off them. Then put them in a bucket and do 20% bleach and the rest water and this will definitely do this within 2 days. When they're done soak them in some api tap water conditioner or Seachem safe (any conditioner without the slime coat). This will neutralize the bleach. Of course you would wash the rocks thoroughly before doing this and this should be fine. If you want you could then re-cure it to to be 100% sure the rock will not change your params.