This seems to be shifting from Lecherman, who is the soul who should be punished. Going after his advertisers makes sense in one regard, but we are making them respond; I want the weight on David Lecherman.
Filling his theatre with a silent crowd would be wonderful. No protests; but no laughs and no applause. The network will fill it in with recordings, but the live actions will have its effect on that invidious person.
The sponsors are where they can be hurt. Contacting his sponsors directly will affect him. They endorse his pervert messages by continuing to advertise on his show.