Yes it does work... at least for me. The more I avoided public speaking the more scared I was of it. I have since been in a line of work where for the last 7-8 I speak on calls, in front of small and large groups which is part of my day to day. I was really bad at it for a while. It took a toll on my mental health. But therapy, practice and perseverance has paid off and I don't have the same hang-ups with public speaking any more. I am not 100% fluent, but I'm able to say what I want to say and contribute. It takes some time but you can do it.