It works, but somehow fucked up an ongoing save I made. So When I did this, and went back to continue my latest, legit game (Chp 1, Level 6 Well Done difficulty) the save file loaded without enemies.

Thanks @Mironn.. but I decided to TNT-hop as suggested by another guide. It was super fun :D

If you want to complete this achievement legitimately, you can:

1. Go to the first room (art museum) on the left, kill the zombies behind the innocent, kill the cultist on the left, pick up TNT from the secret behind a painting of a woman with a baby,

2. On the left from the exit there is a bundle of TNT in the corner, you need to pick it up,

3. Go behind the flame key building, look up so that you can see a window (it's located behind the right side of the building), boost yourself up with a dynamite jump (first make sure, that you lure the innocents away, throw a stick of dynamite under yourself, then move a bit forward and jump before it explodes), kill the zombie, cultist and grab the dagger key,

4. Next go through the same alley and find a crack up on the brick wall, blow it up and boost yourself up again with a dynamite jump,

5. Enter the last room of the level and hit the end switch before a choking hand gets you. ;)

How is it even possible to complete this legitimately? I tested if I could evade some of the map triggers for explosions BUT there are at least TWO places that the game decides to blow up "Innocents". And you NEED to go through there to get two keys, otherwise you won't get further in the level :(
Innos (and sometimes cultists) are instagibbed by the scenery exploding AS SOON AS the Innocents are STARTLED!
I tried luring innos away, by startling them with ONE tommygun bullet in their vicinity (it never hits them) and yet, the dang scenery explodes and at least one of them dies, GAH!
The place in question is right up the road from where you start and to the right.. you won't be able to access it until the first airstrike comes in.

that is fucking hilarious

holy sh*t dude, this thing working lmao

wtf is this actually work lmao?