How-To (delete/manage voicemails from Asterisk CLI)

Is there a known way to delete voicemails from an Asterisk 1.8 / FreePBX 2.9 box using one of these approaches?

#1: You have SSH’d into the box and have the Asterisk CLI open
#2: You have SSH’d intot he box and have the CentOS CLI open

I don’t want to just ‘kill’ files, more along the lines of this.

Seeing what VM is on the system
Seeing who has VM (which exensions have VM)
See who has their MWI light on (I can turn this off/on), but
I do not know whos is on (only can turn it off/on with SIP notify)

I would like more than just this

voicemail show users for default
rm /var/spool/asterisk/voicemail/*

Thanks for any tips or suggestions.