I don't mean to sound snarky, but I don't see how rules will be relevant when he's so comfortably broken vows... Vows are much "stricter" than rules.

Uhmmm full disclosure would be a good place to start, but people know how to erase their tracks, eg email, text, call history... Guess its worth a go though.

In all honesty, I really don't think this is a good idea, but I also honestly wish you well.