What is the Void Glitch in Gen IV and how does it work?

Question

I recently saw some people discovered a new glitch in Gen 4 about 6-8 years after its release! It involved going into some building and glitching yourself to the black void surrounding the map. Using a walk-counter you have to glitch yourself to hidden parts of the game where no map loads and can catch mythical event Pokemon. How does that work? is this true?
Some video links:
https://www.youtube.com/watch?v=VrhHXG3cuAw
https://www.youtube.com/watch?v=aJMeRwJsqmc

Thank You!

Answer 1

Yes, it is true.
Go to this link to know how does it work: https://bulbapedia.bulbagarden.net/wiki/Tweaking