I've heavily worked out for 2 hours and worked in the office for 8 hours with a cloth mask without wetness issues. My experience may not be the same for others, but 15 minutes is an exaggeration. As early as April 2020 there was research indicating 2 layer cloth masks were at least 70% as effective as surgical masks, and the ones I have seal much better! Not to mention most people are wearing poorly fitted accordion style masks, not wearing N95 masks.