I'm quite a fan of nutritional supplements. Anyway, I found this article about the supplement "N-Acetylcysteine", commonly abbreviated to NAC; "N-Acetylcysteine Reverses Cocaine Induced Metaplasticity" http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2661026/
It struck me that maybe it would have a similar effect upon a Porn addiction? The supplement is also mentioned in this article from the YBOP site http://yourbrainonporn.com/introduction-to-behavioral-addictions-2 from which I quote "N-acetyl cysteine, an amino acid that restores extracellular glutamate concentration in the nucleus accumbens, reduced gambling urges and behavior in one study of pathological gamblers (89), and reduces cocaine craving (90) and cocaine use (91) in cocaine addicts."
More information about the supplement N-Acetylcysteine can be found here http://www.raysahelian.com/acetylcysteine.html . I linked to this site because it presents very balanced reviews IMO, without making incredible claims.
I've used NAC myself many times for other purposes; I've found it great for reducing congestion when I have a cold, in fact I gave some to my mother and she swears that it was more effective than some commercial decongestants. It's supposed to be very protective of the liver and is used to treat Tylenol overdoses. Personally I've found that when I use it it has a nice balancing affect on me psychologically. The supplement has also been recommended by another forum member for Prostate issues http://www.reuniting.info/node/10991.
NAC seems to restrict output from mucous producing glands and I'm speculating that this might be how it helped the other forum member, by reducing congestion during abstinence? I wouldn't go overboard with this supplement but I'm going back on it at a dose of 600mg per day which is a commonly recommended dosage.BTW, just to be clear despite my forum name I am not a Doctor of any kind.