I watched enough to lose count how many times he waved the bag around, I didn't skim that much. You can spin his reasons all day long, but to me it was commercial overkill, and didn't come off to me as being all about the hobby. As Duane pointed out, accuracy comes via weight, and one can always test salinity with a hydrometer. He talked about creating a database regarding salinity tolerance among the various species, well that's how real data would/should be collected, not by guess or by golly using teaspoons and tablespoons. I've been using kosher salt (pure NaCl) from the grocery store for forever. People with larger systems should be advised to buy from other bulk sources, such as hardware stores etc that sell bulk "pure" NaCl. Had he waved that kind of advice around even a fraction of the times that he did his new Fritz salt, that would have been what I would consider helping the hobby.
I'm not so great at math, just wondering what would be the advised weight per 100 gallons in the case of using salt as a once-in-a-while preventive measure (as opposed to the 3.5 lb per 100 gallons Duane uses for ich treatment)?