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