Reiki and addictions

I was delighted to meet up with one of my former reiki students over the weekend. Mike was visiting the area having moved out to Spain. Interestingly he has been having a lot of success using reiki with addictions and specifically in using the 'harth' symbol. What sort of success has anyone else out there had with addictions and did you use the same symbol as mike or bring others in? I would be really interested to know.