They are not high quality. Those are also for the person that is sick to wear, not the healthy individuals. Not sure how much the work to be honest.

Even when healthy, I wear a mask when traveling. I know it doesn't prevent much in terms of keeping me from getting sick (still, something is better than nothing), but it does keep my sinuses from getting dried out (which is not only uncomfortable but opens you up to infections).

I wish these masks were on every airplane. JAL does actually provide them, maybe others need to catch on.