Not sure why that other thread closed, but the source of original recipe debunking is probably "The Big Book of Secrets"... but that is not a reliable source either (as compared to KFC themselves). Here is a recipe I found online from someone who claims...

" I worked two years in high school at KFC and later in a factory that made dehydrated hash browns. The spices were very similar.
2 cups flour
1/2 teaspoon MSG (optional)
1. 2 teaspoons salt
2. 1 teaspoon white pepper
3. 1 teaspoon black pepper
4. 1/8 teaspoon rosemary
5. 1/8 teaspoon thyme
6. 1/8 teaspoon marjoram
7. 1/8 teaspoon basil
8. 1/8 teaspoon savory
9. 1/8 teaspoon sage
10. 1/4 teaspoon garlic powder
11. 1/4 teaspoon onion powder
Walmart brand poultry seasoning is very close for items 4 thru 9 and a teaspoon of that is Ok.
The chicken is dipped in a milk and egg dip before it is breaded. Use a pressure fryer, they are becoming more popular for turkeys and available for around $100. The chicken was browned to the color you wanted and then sealed and cooked for about 10 minutes after it started to steam. The old KFC used beef shortening to fry with and the chicken was never frozen, it came packed in ice. The chicken was cut into 9 pieces, two wings, legs, ribs, thighs and one keel or breast. The chicken was prepped by removing any fat, twisting off the tails and cracking the thigh so the heat would penetrate into the thigh. Drain the chicken after frying either on a rack or on paper towels keep warm and serve. The chicken was the least greasy if served after about 1/2 hour after cooking.

I would have to dispute the claim that the flour used by the Colonel only consisted of 4 ingredients. There was definitely rosemary and thyme in the original recipe flour. They did use another flour for the extra crispy which could be what was tested."

In the other thread:

2freaky4church said:

I made some fried chicken with just flour, salt and black pepper and it tasted exactly like KFC, to the point where I wondered if it was supposed to be II secret spices not 11

there is a product you can buy in the asian grocer nearby called "chicken breading" and that also tastes like KFC

ZombieKitten said:

But which KFC?, original (the claimed herb spice flavor), crispy (the salt and pepper), or hot (the same as cripsy but with red chili powder too?)

I've only liked original, the others taste like any other fried chicken (including homemade).

ufoclub said:

oh gosh, I don't think we have so many options here! I think original?
definitely NOT zinger, that tastes like cayenne pepper

I think they use sparrows in New Zealand