maybe it's just me, but i think i'll go with the guy who's worked in a board shop for 10 years waxing boards. especially when he's saying the same thing every other guide is saying.
it makes perfect sense to me that scraping against the grain could damage your board. the scraper could easily catch in the grain. scraping with the grain that's obviously not a problem.
but hey, if you want to wax your board that way, more power to you.