Selective Mutism charity??

Right now I am currently reading A Quiet kind of Thunder and the main character is mute. I have read a book a bit like this before where the girl refuses to talk because of kinda traumatic events.

These stories opened my eyes and I would like to try to raise money for SMiRA.

So I was think maybe I could get sponsored to stay silent for a whole day. But could that be inconsiderate or offensive? Opinions???