The script will work fine on a left hand screw, if the initial setup is done in the proper way.
The key is to create the left hand helix (LH), just like the initial right hand helix (RH).
Then move the LH helix to the Left of the bottle, then FLIP the moved LH helix.
(It will be necessary to have a new blank screw/cylinder located to the left of the initial bottle.)
Then run Michaels script, with -90 rotation, because the array is done from left to right.
This preserves the Counterclockwise rotation of the bottle.
After the Boolean(s) have created the LH screw, in TOP view, rotate the entire LH screw clockwise about the center of the bottle, by -180 degrees.
This places the LH screw at "top of MoI screen."
The original RH screw is at "bottom of MoI screen."
(The above steps produce a LH screw which is equivalent to Barry's mirror method IHMO, (I think).)

Geometry remarks on LH, RH, CW and CCW, which may or may not depend upon the position of the person viewing:
A RH screw remains a RH screw, regardless of how it is rotated in MoI.
A LH screw remains a LH screw, regardless of how it is rotated in MoI.
The bottle needs to rotate Counterclockwise (CCW) from the TOP view, at all times.

If the bottleCutter and or either screw is rotated about the X-axis, from the TOP view, the bottleCutter will be rotating Clockwise (CW),
which is Opposite to what is desired.

But if the bottleCutter is rotated about the Z-axis, from the TOP view, the bottleCutter will still be rotating Counterclockwise (CCW),
which is what is desired.

- Brian

Additional remark:
The bottle needs to be pushed "gravity downwards" by each screw, or it could become airborne.
Looking from the Left side of the machine, the LH TopOfScreen screw should rotate CW.
Looking from the Left side of the machine, the RH BottoomOfScreen screw should rotate CCW.

(One UTube video has the bottle rotating CW from TOP view, which is opposite from our current models.)