Can you recommend good at-home treatments for sciatica?

Core Exercises. Typically core strengthening exercises are the best to help relieve pressure and forces in the spine. I would try and google some or look them up on youtube to see descriptions. If you can do them yourself, wonderful otherwise ask your doctor to get a referral to a good physical therapist for further assistance.
Avoid aggravating. Sciatica often resolves on it's own if the aggravating sources such as bending, lifting and twisting can be avoided. Some have found ice or heat to be helpful if back pain present. Avoiding sitting in straight back chairs for more than 30 minutes can be helpful also. Recline your seat back if riding in a car and avoid more than 1 hour without a break. Get a lumbar MRI if symptoms for 6 weeks.
Several. Time, activity modification, guided exercise, avoiding prolonged positioning, traction, over the counter medication as well as lifestyle modifications such as weght control, not smoking and regular exercise to name the most indicatd methods. Only 10% of sciatica patients with a disc herniation end up needing surgery usually failing 12weeks of treatment.