You need waterfox browser and clean flash to be able to do this method of the train glitch. It is by far the best recreation of the original flash on chrome experience and way less laggy than flashpoint.

Waterfox: https://www.waterfox.net/download/ Clean flash: https://github.com/CleanFlash/installer/releases/tag/v1.4

You spam right-click and move your mouse very slightly so the character moves and then you just go through it. It takes a bit of practice to be able to do it regularly. It is a little slower than the old way but it's still faster than not doing anything

newer vertions of waterfox doesent work anymore download pale moon insted https://www.palemoon.org/