The results of the previously documented approach have not been incredibly good. The goal was to fine tune a set of mangling rules so that it would be possible to find “hard” passwords not attainable by brute force, statistical approaches, or hand tuned rules. It does find some passwords, even on lists that have been heavily attacked by scores of other attackers. It is however far from being a game changer.
You will find a sample of the generated rules here. It was generated by analyzing 1976 rules with a custom wikipedia generated dictionnary (18224931 lines) against the rockyou password set. To use it with JtR you just have to remove the [NBPWD=xxx] part and paste this after a rule header in john.conf.