Actually you may joke but when I asked a highly respected speech therapist what she thought was THE most effective exercise for a PWS she said the same thing. Cancellation. This was back in London in the 1980's. She said it's very challenging to do, it's inconvenient and embarrassing to say the least but she said that's the one thing she has seen have the most positive effect on PWS. This was somebody who had spent her working life in the field so I valued what she had to say. I could never do it, I tried several times but I found the embarrassment too much, once I'd finally spit the word out the last thing I wanted to do was pause and repeat it. I just found it too difficult (and back then I beat myself up about not been able to follow through on it). Funnily enough a few years later I met a random man in the street who noticed I stuttered and he proceeded to tell me how 'cancellation' had helped him. Almost like a cosmic nudge, no use though, despite a few disastrous attempts I still couldn't manage to pull it off. Perhaps it's possible for people who are starting from a more fluent place. The point isn't of course that you instantly say the word again smoothly and I'm not sure if you keep on cancelling until you say the word fluently or you just cancel once (it's been a long time). Anybody intrigued though should research it more for the correct method. There's a lot more to it than the chatgpt answer.