To disable the virtual printer mapping in Citrix, you need to deploy a Citrix user policy to disable the drivers of the virtual printers.
The policy is based on the driver name. So you need to make sure that the driver name is correct.
Here are the drivers.
Microsoft Office Document Image Writer Driver Microsoft XPS Document Writer Microsoft XPS Document Writer v4 Send To Microsoft OneNote Driver Send To Microsoft OneNote 2010 Driver Send to Microsoft OneNote 15 Driver Microsoft Office Live Meeting 2007 Document Writer Driver