In order to define a contextual action for seismic layer processor nodes, you need to put your Python script in your Python directory under a directory called Contextual_Layer_Seismic_Processor_Node.
Go to Tools->Options->Environment->Python Scripts (or Tools->Options->Python->Scripts in INTViewer 5.2) and click "Refresh from Disk". Your script should be listed automatically.
You will now be able to execute this script from the contextual menu of the seismic processor node:
This script will create and apply copies of this seismic processor to all opened seismic layers.
This script is attached to the bottom of this article.
The result after the script executes should look something like the following.