The area to change voicemail settings on the Rezound is grayed out, won't let me mess with it.
Yes, I deactivated Google voicemail from the website.
Sent from my Nexus 4 using Android Central Forums
Actually, the settings on the website are irrelevant for your regular phone number, Verizon and Google Voice don't interop automatically like GV and some other carriers. The options should not be grayed out, but the clear message option will only be usable if the phone thinks you have a voicemail message waiting.
Take it from a 20 year phone tech, the only thing a voicemail system really does is received forwarded calls with some additional information to identify the original destination, then it sends a signal to the carrier to tell it a message is waiting for retrieval. For Verizon systems this is returned by dialing *86 or the number defined in Settings-Call-Voicemail-Voicemail Settings-Voicemail Number and this should be editable on the HTC Rezound (it is on the three I have access too with two different software versions), this number is what is used when you press "1", it's not magic, just a sort of speed dial.
The symbol of a handset (some people call it a recording icon) you show in the picture above is a message from the Verizon Voicemail System, NOT Google Voice (GV's icon looks like a speech balloon with a handset inside it). Once you listen to all the messages in your Verizon Voicemail, the icon should clear, if it doesn't then make sure your Call Forwarding to GV is off, and call from a different phone and leave a new message in VM, then wait a few minutes an listen to it and delete it. If the icon still doesn't clear I would call Verizon and work with their tech support.