I don't know how your thought broadcasting works, but when it happens to me, it's not a matter of simply changing my thoughts. The symptom sneaks up on me, and by the time I notice it's happening, it's already deep into my mind. This happens when I'm in a place with other people, like in the psychiatrist's waiting room or a cafe, etc. I have to get up and leave, or grit it out. Sometimes this lasts a few minutes, sometimes a few hours.

Basically what you're advocating is CBT techniques, which I use sometimes to fight symptoms. It works about 20% of the time.