FilteringEnabled is the backbone of Roblox security. It ensures that if a player runs a script on their own machine (client-side), those changes stay on their machine. For a script to be "visible to everyone," it must find a way to replicate changes to the server. Historically, "reanimation" scripts were used to achieve this. These scripts would technically kill the player’s character and replace it with a fake rig that the script could manipulate, allowing for effects like a missing head to be seen by others.
Mesh Manipulation: The script attempts to set the Head mesh ID to 0 or a transparent asset. While this works perfectly on your screen, FE usually prevents other players from seeing the change. FE Roblox Headless Script- Visible to everyone-
If you'd like to explore the safest ways to get this look, tell me: FilteringEnabled is the backbone of Roblox security