well IMO the words that are being talked about are good to get you started. Those words get the tongue to go through the right motions, and allow air to be put into the call. Not nessisarily the right kind of air though, but that is another subject.
Some of you are using words that make you turn on the note and cut off the note with the front of the tongue twit...... some of you are using words that use the middle of the tongue. like quack some are using a combination like quit or tick... In my mind whatever is most comfortable for you. I think it is handy to know how to use all of the tongue movements that have been previously mentioned. I don't realy say anything into the call anymore I just use the tongue in those movements to turn on and cut off the air. Jim James of Carlson calls calls it gating. I can then add or take away(in theory) larynix fluctuation. This is what some refer to as grunting or growling into the call to get the sound I want.
I use the middle part of my tongue for most stuff ...quacks....like gwick
I use both the front and the rear for single cut feed at different times. like kick kick kick and tat tat tat.
Double cut (rolling feed) ticka ticka ticka....
Bouncing hen quita quita....
That is my take on it for what it is worth....well you asked for it.