Yup. someone did advise that you soak them in vinegar...that was after you described and posted pics of the rocks themselves. These were not your normal rocks, these rocks had tons of crevices and crags in them. However, I believe the method didn't include all the other steps you took. Those rocks are more than cleaned out at this point.
(Oh, that someone was me).
Rinse them in hot water until vinegar smell disappears.