Yes, that sounds correct. I thought the idea, though, was to make the salt non-obvious for this reason. I would hope people aren't storing passwords in a table

Yes, that sounds correct. I thought the idea, though, was to make the salt non-obvious for this reason. I would hope people aren't storing passwords in a table with a "salt" column, but I don't really know. But I think you're right: if you know the salts and you want to use this approach to go after a small number of high-value targets it could work.