That is as long as it is not from a ruptured (prolapsed) disc. If the disc is ruptured the pressure placed on the nerve by the disc and it’s former contents will only potentially dissipate gradually over time. And even then as the vertebra sink and settle into a new position pain may continue.
On the other hand if your sciatica is the result of something called Piriformis Syndrome it is relatively easy to resolve. The Piriformis is a muscle in the gluteal region it runs across the lower part of your pelvis from the Sacrum (sacroiliac joint) to the hip. It’s purpose in life is to externally rotate the hip, that is to turn your leg and foot outwards. Now for some reason the sciatic nerve will run through the muscle in some people rather than under it. This causes a problem if the muscle becomes tight because it can pinch the nerve and cause sciatica. Given that the cause is tension within the muscle, releasing that tension through massage and stretching will resolve the problem. The key point to note here is that the pain starts in the muscles of the gluteus region (your bottom) rather than in the lower back like the other causes of sciatica.
If you have a bulging or protruding disc then we would need to be a lot more careful in terms of stretching and exercising. However with appropriate massage and stretching and exercise it is possible in most cases to release the tension in the muscles that are causing the vertebra to put uneven pressure on the disc which in turn causes it to bulge. If there is no longer uneven pressure on the disc from the vertebra, then it should stop bulging and it will not press on the nerve and symptoms will be relieved.
There are other causes of sciatica which generally are not going to benefit from massage directly although sports massage will potentially help relieve tension that occurs as a result of compensation you make to try to minimise pain.