In order to define a contextual action for outline layers, you need to put your Python script in your Python directory under a directory called Contextual_Map_Outline_Layer.
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 outline layer:
This script will create a seismic slice based on a 10 inline units by 10 xline units square centered on the mouse position when the contextual menu was opened.
This script is attached to the bottom of this article.
The result after the script executes should look something like the following: