If the word with a B is pretty isolated I usually have to ramp into quickly with some other sound. If my vocal cords are moving it's easier to do a soft B. What I always think is funny about stuttering is that we're actually having a hard time STARTING the next sound. I've always had a hard time getting off of Sss, another unvoiced sound (vocal cords not needed). A friend said something about me "having a hard time with S's" and I said "I'm great at S's! Listen to all that Ssss!" just can't start the damn ee sound.