In order to define a contextual action for time slice layers, you need to put your Python script in your Python directory under a directory called Contextual_Map_Time_Slice_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 time slice layer:
This script will create two seismic slices, based upon the position of the mouse where on the slice 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: