In the version I was taught it is used by the Reiki master to separate the energy of the teacher and student after attunement. I tried it to see if it would separate my energy from a psi vamp I was having a phone conversation with who in addition to draining my energy was giving me her headache. It was finally dawning on me that when ever I talked to this friend I would start out feeling good, even cheerful, and after a few minutes I was ready to crawl into bed for a nap and had a pounding migraine like headache focused right in the third eye. Actually it felt like a spike was being driven into the middle of my forehead. The friend would always say at the end of our talk how she felt SOOOOOO much better and a few times mentioned her headache was now gone. Well I sketched SHK and CKR to clear my energy and Raku to separate us. The friend brought the conversation to a quick close and within a couple of minutes the headache was completely gone.:woohoo:
After that I finally believed that some people are psi vamps and I started experimenting more with Raku. I like to draw it on my aura along with the other symbols to help keep me from melding with everyone else's energy like I used to do as a very leaky empath. I also use it after sending reiki to others as well. One time when I was feeling awful cranky with PMS I treated my Mom's aura like that before she went to bingo and I felt like I was being shoved away from her by a wall of energy. I hadn't realized I radiated so much yuk at times like that or that the treatment was so effective at repelling bad vibes!!! I tried this on her as according to relatives who go to various bingos there tend to be cliques at each one who make nasty comments and other wise act rude to anyone who wins outside of their little group. I wanted to protect my Mom from their vibes and ended up repelling myself :P