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