Firstly, as a technical nitpick, osmosis by definition is the diffusion of water across semi-permeable membranes. Stuff that is not water cannot move by osmosis. What you are worried about is stuff like the coating being able to just diffuse through your skin.
That said, having trawled through the companies literature [1], they actually only claim micron scale particles. For reference, your cells are typically 70-100 microns in diameter, so these particles are still comparatively huge. They are likely larger than most bacteria you will see.
Furthermore, since they are both hydro and fat phobic, they'd almost certainly have a very hard time diffusing your your skin, since your live cells have membranes made of (basically) fat, and then enclose a space that is mostly water.
[1] http://www.spillcontainment.com/sites/default/files/FDA%20an...