Someone solved this once by configuring a voice menu to answer & direct the call (to the single phone): started with the heard-so-often-everyone-ignores-it line

Someone solved this once by configuring a voice menu to answer & direct the call (to the single phone): started with the heard-so-often-everyone-ignores-it line "this call may be monitored or recorded for _______ purposes; please press 1 for ..." and the sting subject fell for it when calling. Notification of recording made, implicit permission granted for continuing the conversation.