BTW - a number of small scale studies have found the supplement N-acetyl-cysteine (NAC) can reduce OCD symptoms and also boost the effectiveness of antidepressants for OCD (Oliver G, 2015,
PDF). There is a large scale international study currently underway to confirm this. NAC is generally a safe supplement with few side-effects so is worth a shot. It is used medically to protect the liver in cases of paracetamol/acetaminophen overdose and has many
other uses. Doses of 1,800-3,000mg/day split across the three main daily meals seems to work (start with one dose per day of around 500-600mg and increase by by the same amount every 2-3 days to avoid triggering diarrhoea). NAC is best taken on an empty stomach about an hour before meals.
HOWEVER, be aware that a recent
study found NAC may increase the risk of lung cancer in smokers, or those with some specific lung diseases (note, it doesn't cause lung cancer, only maybe reduces the ability of the immune system to detect and destroy existing cancerous cells). The results have been the subject of much debate because there are many other studies showing NAC protects against lung cancer so it is probably not the final word on the subject. FWIW, I'm a lung cancer survivor and have take NAC for over 11 years because it is the best thing I've found for reducing fluid buildup in my remaining lung.
PS: as for all herbal remedies and supplements, check with your pharmacist or GP before taking NAC while on any prescription medication.