In one of Walter Lewin's famous lectures, he takes a small container almost completely filled with mineral oil and grass seeds (I'll keep looking for the video to link to it). He connects two electrodes to the container and the electric field that is produced polarizes the grass seeds, aligning them in the direction of the electric field lines. I had a few questions about this experiment as I am interested in reproducing it.
What material should be used as the container?
Does the type of oil matter?
What voltage is required?