Is there a way to suppress vmail unavail or busy options?

I have Asterisk set-up as solely an inbound voicemail system. People can only call-in and leave voicemails, hence, when users edit their outgoing greeting, it doesn’t make sense for them to hear options from VoiceMailMain to change their busy greeting or unavailable greeting. Is there an easy way of suppressing the users of the system from hearing that recording their “busy greeting” is an option?