I am so confused

[Yuri]

Yes, it can be played like that, but mostly it was played the way I described. There are some who even play it quena-fashion. You can, it's just that the traditional way you can vary the pitch and sound quality enormously by changing the mouth cavity. You can play (on some instruments, at least) as much as a fifth or so without changing any fingering, just on one position, but altering the mouth cavity. You can even sing, or at least hum into it.

[NZJLY]

I have been trying the method you describe, but I seem to get a clearer and stronger note with a pursed lips blow.
The smaller the Koauau the more you can bend the note. But even with the bigger ones the ability to alter the notes, makes it very hard to tune to a modern musical scale. I will freely admit that I have adapted the Koauau into something different to traditional, but I also try to spread the word about traditional Maori instruments. I usually carry a Koauau and sometimes a home turned Putorino with me to show people that are interested.
Just as an aside, instead of the traditional method of making Putorino (splitting and carving), I turn them on a lathe, cut them in half (across the middle) and turn out the inside. It gives me the ability to experiment with some of the dimensions a bit more.

John

[Yuri]

The traditional playing style was not after clear, flute-like tones, neither was it particularly concerned with exact pitch. As noted above, traditional Maori music is not really comparable to European (or for that matter, Far Eastern, Indian, etc etc) music.
As an aside, 30mm inner bore feels far too wide, at least compared to what's in museums. I make them with 15-20mm at most. Here's an example, made from ostrich bone. (Yes, that's not traditional, but for some obscure reason using human bone (the traditional choice) is frowned upon, can't think why...)



The double hole at the back is for suspension, by the way.