Meh, Its like potato (Po-tay-tow) potato (Po-tah-tow)
No one uses the later, that isnt a word, that phrase only works when one of the options is wrong!
The intent of the phrase means it only works when <i>neither</i> pronunciation is wrong. That's why it's supposed to be "to-may-to, to-mah-to," since both are used and considered correct in different parts of the world.