All speech therapies online who claim to remove stuttering are purely based on testimonials unfortunately. There is not yet a mondane recognized technique or tool to remove stuttering afaik. However, in my own opinion, therapies focus on fluency shaping techniques and secondary behaviors. I advocate to focus on the primary behavior instead. [In this post](https://www.reddit.com/r/Stutter/comments/xdh860/what_if_we_completely_forgot_that_we_stutter/) you can find resources regarding the psychological part of primary behaviors and how to approach them.