Forever Glue is a very low ULTRA-infamous object from the MORBID-infamous episode Stuck in the Wringer.
Why This Glue Should Stick Itself To The Scrapyard Forever[]
It is originally used from the "genius" Patrick, to get SpongeBob unstuck. Who knew it would glue him there? Somehow tears get SpongeBob unstuck from the forever glue... Wait...why didn't Patrick know how to remove the glue? Anyway, this object caused an incredibly irritating and annoying episode.
The idea of a glue that sticks forever is also a stupid idea, since you wouldn't be able to get things unstuck with it, no matter how hard you try.
Just like Snail Plasma, this is the plot device of the episode.