There is a difference between talking more and talking more. Talking more because it's required from you (at the job) won't really help, I agree. But talking more because you just let yourself go and stop caring about stuttering will help because you have managed to psychologically turn the switch. You won't be fluent but I have no doubt your stuttering will decrease. I'm slightly managing to turn the switch psychologically into a 'fuck it I will just say whatever the hell I wanna say' mindset and I've noticed a bit more fluency. Still falling back into my old mindset too much but I'm working on it.