I think it is more likely that Random seed is used to determine where along the waveform to start. The waveform itself is defined by the other values in the dialog.
Unless you want to toggle the display for the wave step in the actions panel and click ok 50 times during the batch to generate a new Random seed you will need to replace the wave step in the action with a step that runs a script to apply the wave filter.
If you post the setting you used in the wave filter dialog( or a screenshot of the dialog with your settings ) I will try to create the script for you.
If you want to create the script yourself you can install the scriptlistener plug-in if it is not installed and run the wave filter several time to get an idea of the seed range. For example when I tried this using my setting the seed was a 8 digit number that started with 1763. You can use Math.random and Math.round to generate the other four digits.