The most effective treatment for OCD is the technique of graded exposure to the uncomfortable situation, and a prevention of the usual response of trying to escape from that event, (usually abbreviated to ERP). I have found in my practice that this technique works well with people, whether the fear is about an external event, such as germs, or an internal event, such as a scary irrational thought. In both cases, there are well established cognitive and behavioral procedures where one learns to walk towards the uncomfortable situation, whether it is a external from your body, or inside your head.
On a slightly deeper level of explanation, with OCD, the germs or irrational thoughts are not the villain. It is the constant attempts to ESCAPE from the discomfort that keeps making matters worse. In general, the more you try to escape from the discomfort, the more fearful you may become.
OCD is the most crippling of the anxiety and fear disorders. It is controlled by a primitive part of your brain which unfortunately can function independently from your more rational self. This is usually called the “Fight or Flight Response”. In anxiety disorders this mechanism has got the upper hand.
In ERP therapy it is possible to teach that primitive part of your brain to “cool it”. ERP teaches you how to act as if you are not in danger, despite the fact that the primitive animal is screaming that you will die if you don’t try to escape. You won’t.
The more you learn how to put the fear mechanism to sleep using ERP, the more you can go through life using this skill in any area where fear raises its ugly head.