Sciatica is a fairly common symptom of lower back pain. Personally, I've gotten more relief by combining physio and chiro treatments. No it does not subside quickly. Used to take 3-6 weeks to feel semi- normal. Extreme compression on the nerves can require hospitalization
Also depends on the root cause behind the sciatica. Is it a compressed disc, DDD,fragmentation, a fracture, a form of stenosis? You may need to see an orthopedic surgeon or neurologist. As long as that root cause persists, the sciatica, and other symptoms, keeps coming back, and get progressively worse.
Treatment has come a long way since Ham Hall's text "The Back Doctor", but his book is still a good manual for back care for yourself.