Which would be the problem, since most wordlists does not contain all the clear-text passwords. Unless you can compile one yourself, which would take a very long time and lot effort.
Edit: Even then it may or may not contain all the clear-text passwords, which I would in turn convert to traditional brute forcing, using several Nvidia Graphics cards, perhaps in a clustered environment to speed up the process. But again depending on the size of the hashes it could take a long time to crack.