Olive oil on your hoo-hah?

Okay, don't call me crazy yet. I've been told by multiple midwives, that every night before bed I should take a few drops of olive oil, and rub it on the outside of the vagina, every single day. The reasoning is that by the time of my labor, the skin will be softer and easier to stretch, so that during delivery, I won't rip as much. So many people say it's true and it works, but what do you think? Comments? Personal experience? I'd like some opinions before I start lathering up like a baked potato.