I wasn't a teacher, but I was an army interrogator for a while. At first it was a train wreck, but after awhile I got used to the situation and stuttered a lot less. Looking back on it now I'd say I was pretty terrible at my job due to the stutter, but towards the end I got much better and felt I was pretty average. One thing I noticed is when I took a break from the work for a while my stutter was always bad when I stated back up again.