If vision does what it is meant to, an easy way to market it would be images showing a clear difference of a bit of glass, split down the middle, one side regular clean, the other vision.
Simple, effective and instant.
Or, video of 2 identical houses, cleaned by the same cleaner, one 30% faster.
Basically anything to promote the claims that are made about the product.
Would negate the arguments about what it does and doesn't do.