Best Curtido Recipe (Salvadoran Slaw) for Pupusas, Enchiladas, Pastelles, etc.

There are lots of Curtido recipes, but they all seem to be missing the authenticity of Salvadoran Curtido. Here is my take on Curtido, and one that is highly recommended within my Salvadoran family. This goes great on Pupusas, Enchiladas, Pastelles, and just about anything else! Let me know if you have any questions or comments!
Ingredients:
Note: The ingredient amounts may change slightly depending on the size of your cabbage. When in doubt, start with less spices, then add accordingly to taste.
1 Green Cabbage, or 1/2 Large Cabbage
2-3 cups Apple Cider Vinegar
4-6 cups water
Boiling Water (1 quart or more)
1-2 large carrots shredded
1/3-1/2 White or Yellow Onion, Minced
1-2 tsp Oregano
1-2 tsp Red Pepper Flakes (optional, add more for for spice "kick")
2-3 Tbsp Salt (yes, this sounds like a lot. But remember most of the salt will be in the liquid, and you won't be eating it. This helps with flavor and fermentation of the slaw)
3-4 pinches Brown or White Sugar
Shred cabbage, and put into bowl or other cylindrical container.
Pour boiling water over top of cabbage, let sit for a moment, then drain boiling water
Add Water and Apple Cider Vinegar at a 2:1 ratio (2 cups of water per 1 cup vinegar) until cabbage is covered. Note, if when you taste test later, it is too vinegary for your taste, you can add some water to dilute it slightly.
Top with carrots, onions, red pepper, oregano, salt, and sugar.
Stir with spoon or by hand until completely mixed.
Enjoy!
The longer you let this sit, the more flavor it will have inside the cabbage, but since we poured boiling water over top, it will be good to go much sooner than other recipes. Store in fridge within 1 day, and you can keep it in the fridge for several months. When you are done eating, you can reuse the liquid for another batch of Curtido. Just follow the first 2 steps of this recipe, then add the leftover liquid into the cabbage. If it's not quite covering the cabbage, you can do this again.