Lifelong stutterer here, 34 now. I agree that the clapping and tapping could cause a problem. A lot of stutterers do develop some sort of coping Mechanism that can help them speak. I roll my hands forward sometimes and gesture a lot- think stereotypical Italian “talking with my hands”. Clapping and tapping seems to noticeable and unnatural and might have just led to problems in the future. Note that a lot of these coping mechanisms some stutterers have can be a form of tapping but it’s discreet and discreetness is something many 4 year olds lack. I’d be worried about teasing as he gets older. I really do think the second therapist sounds better. Giving a stutterer room to speak with no pressure can be important. Stuttering can be tied to anxiety and pressure - even if you are absolutely not pressuring the speaker - seems To play a role. Stuttering can work as a feedback loop in that sense. We’re anxious, so it feeds upon itself and the stuttering makes us more anxious. Speaking slowly absolutely can help, but there needs to be a balance in my opinion between speaking slowly and speaking TOO slowly. I can be talking at a reasonable speed and normal conversation speeds but then my grandmother will tell me to slow down. That pisses me off to no end! Going absurdly slow is just going to drag this out and make me draw my words out in an attention grabbing way. So yeah, you may not be seeing improvements - especially because he is four and speech is all over the place at that age - there is still time for the stuttering to resolve itself I think -but the time spent and the confidence given and the knowledge that his parents will always listen to him no matter how long it may take him to speak will be crucial. Good luck! He has a wonderful future ahead of him.