That’s like saying you cannot really learn music, it needs to come organically. Well you’ll need to learn it first through repetition. That’s how our brain works. Just go to a coffee shop and talk to the barista and stutter voluntarily. Maintain eye contact, speak slowly, pause and breathe. How do I know this works? I did this for 6 months, day after day approaching strangers and stuttering on purpose. At first it was terrifying but now it’s become easy. The side benefit is that I’m now completely at ease speaking with others, and I therefore I speak much more fluently. If I block, I just take a pause, breathe and speak again, while maintaining eye contact and CONFIDENCE. The other person doesn’t seem to care or even notice.