Sciatica pain sounds more like a back problem, than a postwithdrawal problem. I've seen a chiropractor for a year, since I first started tapering off Klon. My muscles kept going into spasm because of Klon w/d's, including my neck, which really messed things up in my neck vertebrae.
With a chiropractor, no drugs are needed! And it can really help. Also, any kind of "relaxation" will help.....a massage of the back muscles, hot bath like [...] said, heating pad, anything along those lines. When I was a massage therapist, I often found that sciatic pain came from the sacral area (lower back) so that might be a good place to start. I find that starting with the easiest things first, (like heat, ice, and massage), then working up to the most complex solutions.....works pretty well.