That doesn't even work with hiccups. It's true anxiety, self-awareness and psychological factors contribute to how pronounced a speech impediment is. I was taught the Maguire program twenty six years ago and it's advice had always stuck. Own it. It's always going to be there, even if we manage consistent fluency every day it's still there. It's nothing to dismiss or allow to be a source of shame. It definitely shouldn't be minimised. And every person presents different. How intelligent we are doesn't matter. I'm 43 years old and I still have my moments but I own it and have long since stopped seeing it as a disease to be cured or a myth to be deconstructed. Medical professionals know best though. I can only offer my own perspective that it's something which requires more context and a solution with more complexity than advice I've been given about hiccups before. Didn't work for them either.