In OnyX, there is a setting in Parameters > General > Animated desktop background: where animated wallpapers can be set. While this doesn't seem to work very seamlessly (moving between spaces displays old wallpaper briefly etc.) and doesn't persist over restarts, I wonder how OnyX does this.
Is there some hidden setting where one can do this without OnyX?
Note that my question is not about how to set gifs as wallpapers (although maybe this is what OnyX does?).