Couldn't help but reply to your post.
I developed RSD post-op knee surgery in October. I have since returned to work (thank god for that), but it's been a rough road.
I use a TENS unit while working (I am an ICU nurse with access to a LOT of drugs, thus cannot take anything stronger or that will pop a drug screen.)
BE CAREFUL...regardless of the type of electrose I use, the RSD part of my leg develops patches of bleeding blisters-something between a burn and a rash-that is scarring my leg. Ironically, when electrode are placed above my RSD area and used-no problem. My pain doc says not to use it as my skin will break down and likely exacerbate my RSD, but I can't work without it and am waiting for "blessing" from my employer to take yet another leave for a spinal cord stimulator. (Already more than have been cleared to get one, but told that there is no guarantee that my job will be there once it's healed.)
Road test the TENS-it does give me some level of relief, but at a cost.