I had a terrible phone interview a few months back. I mean absolutely awful. I ended up getting the job anyway. I advertised that I stuttered at the end (I should have done it at the start), and that my stuttering is much worse during situations like phone and job interviews. They were very understanding. For me, it helps to advertise that I stutter at the start of the interview. Saying something as simple as, "Before we start, I'd like to let you know I stutter. It can be more prevalent in situations such as phone interviews. If you have any questions about that I'd be happy to answer them." It's amazing how something as simple as this can take the weight off your shoulders. You now no longer feel like you need to speak perfectly fluent. I work in technology as well, and word substituting really doesn't work in this industry. Word substituting is just another form of avoidance behavior. Often it is just better to commit to saying exactly what you want/need to say, as opposed to using tricks to be fluent. When I adopted this model of non-avoidance, my speech got better overall in all aspects of life.