Plugin for Invisibility

Over the past few days I have been trying to find a plugin that will make me invisible, so that I could spy on some suspected greifers. Sadly, every one I have found so far is inactive and no longer works on updated servers. Am I searching for something wrong? Have I not read correctly? Could someone please help? If you are able to find a working plugin, please post the link. Thank you very much

bump. Please. I really need help with this.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Vanish No Packet

Beyond vanish and vanish w/o drop pickup, you can also join and leave silently.

 

Vanish no packet and Spyer should be the two big plugins here. But to be able to use them you also need Spout

 

I've tried both, but it never works. I type in the /vanish and It says ive vanished, but when i stand infront of another player, they can see me. And I have Spout