I worked there is HS. Henny Penny pressure fryers and double breading of the chicken.
Dip in water, bread in a certain pattern in the flour mix, dip in water, shake down the breading, bread again in a certain pattern, load into the verticle fryer baskets, pressure fry for 21 minutes.
When I worked there a few decades before you I seem to recall the dip was a milky color, it was probably a powder mixed with water. Dip, bread, dip, bread and cook. Back then it was put the chicken in the pressure cooker (no racks, just loose pieces into the pot) with lid off for x number of minutes and then slap the lid on to pressure cook. Dump it onto a rack that drained the oil and flip the pieces a certain way to ensure draining. Put into a Cres Cor warmer until sold. I was working the day man first stepped on the moon, not much business that day. I probably wouldn't even recognize the kitchen of a KFC today.
bob