Good question, we are getting ready to deploy a DLP agent that comes with a menulet, and the developer told us there was no option to hide it (my point being that they could if they wanted to as the developer, but there was no client-side solution available that we could find). If there is something we can do, I'd love to know as well.
Can you hide it with a config profile?
We've got an example for the vpn menu item here:
You normally have to control the com.apple.systemuiserver and specifically the menuExtras array that lists included items.
OS X has different types of icons on the menu bars. Hold command down and click the icon. If it can be dragged, then it is a Menu Extra and can dragged off the menu bar, deleted from the computer, or controlled by a config profile. If you want to find it in the file system, look for a bundle ending in .menu in the Resources folder of the program providing the extra, or in /System/Library/CoreServices/Menu Extras/ . If the icon can't be dragged, it is a menu status bar item, and you're likely stuck with it, unless it is created by a secondary app that is not integral to whatever you want to run.