This is from Al, DC5GD.  In keeping with my CW reflector gets the best
info, here it comes.  73 de N1EA

BT

Hello everybody,

This is why I like amateur radio:
I received lots of answers to my question - mni tks dr frds!
To give a little back to all of you here is a little summary of all
comments, advices, hints, tips and tricks:

1st of all:
HAMs are individuals and each has an own style in operating a cootie. It
seems to be the same as with a pair of shoes. They might fit to one
person perfectly but nevertheless they are terrible for an other one
(size 43 is ideal for one operator having feet that are size 43, but for
an other operator having size 46 the 43 ones might perhaps not fit
perfectly - hi hi).

2nd:
Thank you so much for widening my horizon. I thought I had got all
aspects of using a cootie and again I learned that I should be a little
more humble-minded - nobody knows all aspects of anything.

3rd - the summary:
Operating a cootie is moving / rolling your hand from left to right and
reverse always in an alternating way:
. left -> right -> left -> right ....

The classical style is to keep the movement alternating (like a sinus)
all the time. So sometimes a letter will start with the thumb and
sometimes with the index finger.

BUT
There are many other ways to operate the cootie key. All of them have in
common that within one letter the alternating movement is kept strictly.
The difference is only from where the operators start a new letter or
sometimes with a new word.

The "classical style":
Always keep the alternating movement. Nothing more to say.

The "paddle style":
These operators start a new letter like they were using an elbug.
Letters starting with a dot AWAYS start with the thumb, letters starting
with a dash AWAYS start with the index finger.
Or they do it the other way round: Letters starting wit a dot always
start with the index finger letters starting with a dash always start
with the  thumb.

The "always start @ same side"
These ops always start all new letter always with the same finger, some
always with the thumb, some always with the index finger. David, N1EA
does it this way and he is really fast and very accurate:
https://youtu.be/r0EDFjCEoDI

The "random style"
These ops mix all above described styles and take whatever is
comfortable for them

The "instinctive style"
These ops can't say which style they are using. They are doing fine but
when they try to check out how they are operating a cootie they
struggle, the morse code is interrupted or even breaks down. This is
true for many hs cw ops.

Additional note 1:
Some ops advice not to move the fingers. Alex, UR5FIL describes it this
way:
1. Fix the distance between fingers (say 3 cm) and never change it
during keying, Freeze it.
2. The fingers do not work during keying. They are like steel wrench.
3. Touching of your hand to the table is in one point only. This is
point of rolling right and left of your wrench. :)
4. Don't move fingers. You need to roll hand (wrench) against one point
you are touching the table.
5. Start form sending dots (endless R-L-R-L-R-L-R-L... rolling)
..........

Additional note 2:
The question came up if a right-hander should use his right hand to
operate the cootie.
Simple answer: Why not?
I am a right-hander and I operate the straight key with my right hand.
Anyway for paddle operation I use the left hand and I will do for the
cootie too.

Why?
I can make notes while sending standard phases (e. g. "bk de DC5GD/p = r
r r dr om = all cpi ok" with the left hand.
With nearly 60 coils you can hardly change habits (writing with right
hand). It is easier to learn something new (cootie-ing with left hand).
And I have been told that doing things the other way round will keep you
agile and awake.

Little suggestion to the younger hams:

If you have to join regular meetings so often as I had to do you will
remark that after max. 3 sessions everyone will be seated on "his
place". There will be a strictly fixed seating arrangement. It is great
fun to break / destroy this especially when the meeting take place in
the office of the CEO. Everybody knows, that he does not "own" a chair
there but "Why the hell that Al is sitting at my place...?!"
And changing the point, where you are standing / seated also changes you
point of view resp. standpoint. Try it - it is fun and a real
experience.

BUT: Do not try it with the chair of the CEO. My experience is that he
will not fire you (preconditioned you are doing a good job). But your
carrier might stop.

An other method to stop being promoted is to park your car on the
parking slot of the CFO. Success guaranteed by 100 %.
OK - enough kidding.

How wide do I space my contacts with sideswiper?

Experienced HAMs recommend beginners a great gap (distance between
contacts of the key) so that there is a great traveling distance for
the hand / fingers when moving from left to right an vice-versa.

This will slow down the sending speed (bpm / wpm rather small) but
help sending clear and accurate code.

With increasing training the gap can be decreased and the speed will
increase.

Conclusion:
Use whatever kind of cootie style you want to - as long as it is fun,
clear code and you use a cootie!!

Final remark:
Please do not mind that I did not mention most people here personal with
name and call sign.
This is no disregard or disrespect, but if I did it this mail would look
like a call sign book ("Who is who in cootie practice?") with a bunch of
pages.

So be young, have fun, use cooties!

Yours Al, DC5GD