Yeh ive used this approach with a trainer, and used it with a wing yesterday. Its high stakes and therefore much more rewarding than indirect. Theres no messing she knows what this is about and she'll start blushing from the start and you'll know instantly from the moment she reacts that you are in.
Though my biggest problem is transitioning form the opener, this is critical guys if you aint got a way to carrying on she'll keep walking, i feel once you've stopped her you've gotta start engaging her in a conversation or she will think that you just wanted to compliment her and thats is all.