I know several certified reiki practitioners. Some work from their homes. Henry Chiropractic has an Advanced practitioner on staff. There used to be a place down in St. Mary's City as well, not sure if its still there. There were reiki session as St Marys Hospital in the past but I'm not sure if they still have them now the hospital is under the MedStar umbrella.
I've had a treatment. It was very calming. It's different than massage which is about muscles. Reiki is about energy. If I had the money I'd get another session because I definitely felt stress free and had clear thinking for quite some time afterward.