I don't think it's a good idea. Maybe this trick wil help you reduce anxieties and fears of stutter, but it's just a temporary expedient and stutter is not relevant to wrong breath intakes either, at least no scientific evidences. I think it's a better way to eradicate your fears of stutter essentially through cognitive therapies or similar methods. Breathing deeply or similar techniques can only temporarily impact positively but your fears of stutter will still exist, and as time moves, maybe you'll consider speeches as negative experiences then it'll change your personalities upside-down.