Yes, a panhard works on leaf spring suspensions. It does a nice job of keeping the rear axle from moving laterally due to deflection of the rubber bushings on the spring eye and shackles. They are not hard to build, but they are challenging to build correctly. My goals for panhard bar installations are...
1. Level at ride height
2. As long as possible
3. Beefy enough so the bar and the mounts don't flex
4. Utilizing end bushings that will last for a long time with highway use (no heim joints)
5. Make it adjustable for fine tuning
6. Usually mount it at the axle centerline to help lower the roll center a bit
7. As close to perpindicular to the longitudinal centerline of the vehicle as possible for strength and control