It's still working, nexfail again.
Steps for this(This works for me):
1 - Take your knife
2 - Get to the sealed door
3 - Face the door and turn to your left
4 - Now let half of your view to the wall, and the other half to the corner
5 - crouch, sprint, move forward, keep trying until you can't move from your position, and you'll know your in the semi-glitch.