First of all let me say, "Revegging" is not my thing; so I'm not talking from experience.
Now, with that being said, it is my understanding that you really need to "shock" the plant back into veg by giving it way more than a 12-12 photoperiod. Probably at least an 18-6 Photoperiod.
I don't really know how it works outdoors under natural lighting, but good luck!