Here is my own solution. Maybe it helps somebody else.
The 1st problem was that I did not read the docs carefully enough. The text cited in my question continues:
Refreshing the Services menu
Once you have provided localized text for your service menu item title, you may need to refresh the Services menu list to see the changes. One way to refresh the list of services shown in the Services menu is by using the services debugging tool pbs
. This is a command-line tool located in /System/Library/CoreServices
that provides useful services debugging features, such as refreshing the list of services or printing out the current list of registered services. Listing 3 shows an example of a command-line you can enter into the Terminal application to refresh the list of services for English and French.
Listing 3 Example use of pbs to refresh services.
/System/Library/CoreServices/pbs -existing_languages en fr
The 2nd problem was that the command given in Listing 3 above did not work for me. However the command
/System/Library/CoreServices/pbs -update
actually updated the service menu and the localized menu entry was displayed.