The desired function of the mask is to significantly reduce droplet transmission from the wearer. You are not hoping for a 1 micron-tight seal. You are looking to reduce gross contamination (excuse the phrasing). In addition, even a partial reduction in inhaled virus can reduce overall viral load if one were exposed. At its most basic level, something is better than nothing. It's not a question of N95 level filtration, NIOSH, or any other certified standard. Air will unavoidably leak around the edges. That doesn't change the overall value. Yes, a properly fitted N95 mask will filter more effectively, but them's hard to come by, and not necessary, if one of the lower level masks is combined with social distancing. Meanwhile, the people who really could benefit from N95 (think frontline healthcare providers with daily exposure to the virus) would be eternally grateful if their supplies were more robust. Let the general public do what's both effective and efficient in terms of resources by distancing with generic masks, and leave the N95s to the people whose lives depend on them.
I would think the Dust Bee Gones would be happily employed under the current conditions, since they aren't really that effective for the dangerous ultra fine dust particles in a shop.
I'm a former RN married to a family practice doc.