My son started stuttering when he was 3 and by the time he was 5 it had gotten really bad with major blocks. He started speech path around 4 and to be honest it didn’t seem to be working at all(not sure if it was an age thing or just their techniques). We switched to a well known speech path that only does online and I’ve noticed a huge improvement. She employs a method called pause and flow which has really seemed to help.