Grilled Gnasher

After further testing, this food essentially works exactly like stealth. The aggro radius is similar, and mobs will even do the thing where they turn to face you if you get slightly too close. It also reacts the same way to mobs with True Sight (such as the larger aqir mobs in Valley of Honor). With that in mind, it becomes fairly easy to use the food in visions. In my original experience with the food, I had actually mounted up (since you can do that with Rabbit Charms, I assumed it would be fine), which caused the k'thir form to drop and the buff to be inactive. As tale mentioned below, you're able to use the food while the Well Fed buff is still active to instantly regain the k'thir form, which is handy if you're using it in a couple of areas close together. All that being said, there are not a huge amount of useful areas for it and you might get better use out of the movement speed or healing per second food.

OLD: Tested this out in a Horrific Vision. The results were incredibly lackluster, or maybe just not up to my expectations. I had thoughts of the Rabbit Charm from islands in my head and assumed I'd be able to walk right past things, but instead the aggro radius seemed barely reduced. Even mobs that I gave a fairly wide berth to (though of course, less than the normal aggro radius) seemed to aggro like normal. I might be missing something, or it could be bugged possibly. Let me know your results and if I seem to be mistaken, I will edit my comment accordingly.

if u move or get into combat the 10 minute buff fades and it starts draining again
very useful to wait for cooldowns or combine it with [item=174351] to restore 200 Sanity while not loosing any sanity doing it

You have to be transformed into a cultist for the effect to be on. If you use any abilities or mount up the illusion breaks