Interesting topic indeed. I read through the topic and the page it links to here:
http://yourbrainonporn.com/age-23-metam ... ick-magnet
But I honestly cannot tell if this is just a placebo effect at work. A lot of the stuff in that diary is coming through practice. He mentions going out more and more and being able to read social cues better. I'm not convinced the lack of fapping has any input into this or not.
He also quits smoking pot at the same time he quits masturbation, and starts smoking pot when he starts masturbating again... it's not a controlled experiment by any stretch.
Finally, the tone and subtext of that diary paint a picture of someone who is ashamed about looking at porn and masturbating from the outset (seeming based on some kind of religious/moral ideas). Clearly stopping doing something you feel "shameful" will make you feel more confident and good about yourself.
That said, it's very interesting. Here's my theory on the subject: I do wonder if it's a biological reaction, by not having sexual release, your body is looking for the next sexual release and the reason for sexual release is obviously reproduction.
My feelings on this is that it's not that "Suddenly girls find you more attractive" or "Girls start noticing you" it's that
your body heightens your senses so that you notice more girls noticing you. The same number of girls will make eyes at you, but your improved perception allows you to see it and be more confident. So, to the OP, it's not that those women suddenly became interested, you probably just picked up on their interest so gave a better reaction back such as holding eye contact, better facial expression, etc.
It would be very interesting to do a proper scientific study on this. Measure hormone levels, blood pressure, blood sugar and all that and see exactly what the chemical difference is. The upshot of this would be that if you knew the cause you could make a drug to artificially induce the effect.
edit: As someone who likes scientific answers, the study here:
http://link.springer.com/article/10.100 ... 222#page-2 shows that not masturbating increases testosterone. The documented effect of this is higher aggression. I wonder if that's part of it? Aggressiveness will naturally make you seem more confident. In the diary I linked to, the guy said he became less worried about "approaching". Which is clearly an aggressive move. Hmm. Food for thought.
And the answer to "How many days?" is 7:
http://link.springer.com/article/10.163 ... .2003.0236