I have never heard that, and personally would not try it. I know people who will wash their vehicle with dish soap and say it is ok, but again, I will not do that either, as it will strip the wax. Not sure what pedialite will do.
Don't do it. The CDC tracks sales of things like that. Here there was a spike in the sale of Pedialite and they investigated it. Can you imagine the CDC showing up at your door wanting to know why you buy so much Pedialite?