As of 6/17/18, I have completed the Secret Ending, and the day after, I did it sub 6 minutes. Both runs used the same strat so here it is IN DETAIL!
The first two notebooks are a breeze, but timing ACTUALLY Matters! After collecting the 1st notebook, speed to the second notebook. You want as much time between that 2nd and 3rd slap as possible.
This is important: as soon as you are out of the notebook interface for notebook 2, run as if you were going for 7/7 notebooks the old way. the PRINCIPAL cannot show up during this time because if you don't make it by the time Baldi slaps 10 times, he will see you just as you turn the corner, making this increasingly harder as you have less distance between Baldi.
If you turn the corner and Baldi isn't in your rear line of sight, then you have done excellent thus far! Open the door to the Cyan notebook room when you pass it (Press Space to do it in rear view) but DON'T ENTER! This will grab Baldi's attention and keep him from randomly going about. He should appear before you turn the next corner. After seeing Baldi, head for the green notebook.
This is also important: In the entire map, there is 1 quarter that you need, but 2 you can collect: one spawn randomly in the map and the other is in the faculty room nearest to a BSoda machine. You must hope that the random quarter shows up during your travels to the black notebook, or else you'll have to deviate to the faculty lounge. Another thing to note is that you need to collect the quarter in that faculty room. If you have 1 quarter BEFORE passing the BSoda machine, get BSoda before heading over to the Black Notebook.
After collecting the Black Notebook, Baldi should be coming down the furthest hallway from your exit point, which is back the way you came except do so in an attempt to make it to the first red notebook. For the entirety of this next section, your run should be CLEAN meaning NOTHING can screw you over. If something does screw you over, you won't have enough time to grab the notebook without using Bsoda. Collect the 5th notebook.
Before you head to the cafe, use a Bsoda when Baldi appears in the hallway. This is where xemstretch plays a part: perform it on the way to the second red notebook but DON'T use the zesty bar. It will play a role at the end. You ahould be able to use all your stamina BEFORE collecting the 6th notebook.
7th notebook stretch and you still have 1 BSoda. When you make it to the door to the cyan notebook room, just use your BSoda. Don't worry if Baldi isn't in the hallway yet. He will be before the BSoda finishes running it's course.
"CONGRATULATIONS! YOU'VE COLLECTED ALL 7 NOTEBOOKS! NOW ALL YOU NEED TO DO IS GET OUT WHILE STILL CAAAAAAAAAAAAAAAAAAAAAN!"
NOTES BEFORE CONTINUING: The sock puppet still exists. If you see it in front of you, be sure to look backwards and go forward, checking every 2 seconds for 0.25 seconds at a time to see if he is gone.
1st exit: simple, after exiting the cyan notebook room, turn left, walk forward for a little bit, and then go backwards. When you run out of stamina, use that first zesty bar.
2nd exit: whilst looking behind you every so and so, the 2nd exit should be the one at spawn. This one is more simple. Afterwards, however, is the last real threat to you. You must enter one more faculty room and grab the zesty bar. Use it when your stamina is FULLY DEPLETED! Wasting stamina is NOT ACCEPTABLE at this stage of the game. After you exit, go left. It is a more straight-forward path to the exits
3rd exit: make a right and pass by the exit. You should have run out of stamina at this point if you don't foxtrot.
FINAL EXIT: This exit should be the Cafe. Press space to wave goodbye to your frenemies and exit.
