As a person that stutters it is totally not disrespectful. I commend you for having the courage to go out and stutter on purpose. Even at the very worst, if someone went out into public to stutter on purpose to make fun of people that stutter, I would still commend their vulnerability. Even people that stutter will sometimes stutter on purpose as a way of desensitizing themselves. If you have the courage to go out and speak while stuttering, then that is very similar to walking in the shoes of most people that stutter. So don’t worry, what you’re doing is awesome and takes courage!