There's something psychological going on if the idea is that autism is completely caused by the environment and can be scrubbed out with a caustic solution. It's like Lady MacBeth, rubbing her hands to remove the spot that isn't there. Autism is a complex interplay of environmental and genetic factors and it is tied up with the mysteries of brain function, which is the most protected part of the body against external chemical "toxins." It just doesn't make any sense to think you could wash it all out -- it would be like scrubbing your computer to fix the internal wiring!
But all that argument aside, my wife pointed out that the best argument against bleaching out the autism may have been presented on the most academic of all TV shows, The Soup starring Joel McHale. I never thought I'd be citing Jennifer Love Hewitt to cap off a scientific argument, but if it works, it works ... and the lady is right about this: