This is a word I use often. I was always persistent. I guess it came in handy with stuttering.
Many times I talk with parents of children who stutter or adults. They ask me why previous therapies did not work. Like anything else in life not everything works for everyone. You need a connection. I worked at many therapies too but I can tell you that prolonged speech is the best program out there for adults. I use these tools now and barely stutter.