You don't need to be so condescending.
I imagine Hawaiians are much smarter than you give them credit. They probably put their finger on the 2nd string 5th fret and matched the note to the open 1st string. Then they put their finger on the 3rd string, 4th fret and matched the note to the open 2nd string...etc...Much like most players of fretted instruments did. I tune mine with a tuning fork, a technology that has been around long before the ukulele was ever thought about. There is no proof that the phrase My Dog Has Fleas even comes from Hawaii. You would think the mnemonic device would be in Hawaiian.
I'm Hawaiian bro, stop pandering.
Now you're just nitpicking
No, Hawaiians are extremely musically talented, moreso than any other culture on earth. It's widespread and prolific throughout the entire population.
They can just tune by ear. They don't use tunings forks or flutes or chimes or whatever else.
My dog has fleas is not Hawaiian. It's English. It's a learning aid for little kids who are learning to tune and train their ear. They don't use it for very long before they can tune by ear, far younger than you imagine. But most Hawaiians will still think that when tuning. If they speak English, and play ukulele, odds are they know my dog has fleas.
Look bro, you pretend whatever you want. I'm done arguing this point with you. You can just go about your life thinking Hawaiians had tuning forks and sheet music, idgaf,
Enjoy your life, and your own little version of reality.