I can talk perfectly fine for 10-15 minutes per shot, but I can't do it for longer than that. My stammer starts seeping through and then becomes like a snowball effect. I do it by using my bag of tricks, such as changing the tone of my voice, slowing down my speech, subconscious tapping, etc. I can speak flawlessly for that period of time, but I need time to recharge for 5-10 minutes between periods.