I know what the premise is.

[That much was becoming obvious within the confines of this game.]

Dust can work it's way in to the tiniest of openings, and I would argue that it's still necessary. [Though he wasn't making the best case for it] If microscopic organisms are ever introduced you'll be a walking petri dish, and you'll endanger those around you.

Besides- cleanliness presents a better personal image, and makes you more approachable. [Perception is everything]