Sadly, you have better luck if you can start spreading better information. :) That is, just saying "this isn't true" doesn't convince people it isn't true.

Further, I'm definitely game on more information in this field. I think I knew the "left/right" brain was mostly wrong, but that there were some facets that make the exercises worth while. That not the case?

Is it a myth though? I would rather suggest studies are simply inconclusive. There have been studies outside of humans which show lateralization exists as an evolutionary tool. There have also been some in humans ("Sources of mathematical thinking: behavioral and brain-imaging evidence" in Science for example) which shows that they exist in dominant-passive manners, but not in the "all or nothing" marketing drivel that gets sold. Am I missing something scientifically or is the "myth" you're getting at simply the oversold notion of what it means in popular society?

I have to be honest in saying I don't know the science here. I just personally know that I feel a difference in my mental capacity when I switch from programming to writing. That's all that point is about it.

He is just promoting his service through blog posts, have to write something

I use paper most of the time, but for recurring things in particular I've found rememberthemilk to be very effective.