May I assume then that selecting the clear virtual button is actually doing just that ?
Sorry, which button? Are you referring to ZA? The browser? If you refer to the ZA button "clear virtual data" then you are clearing everything from the virtual data including sessions not related to the bank or browser installation of add-ons, plug-ins, etc. As indicated its better to do it with your browser closed. Depending on the size of the virtual data you may need to wait several minutes before all the wipe is performed.