With respect to factories, you should have an N95, good ventilation, and take your beaks outside.
Half of the things you mentioned are things we should not be doing. You get a low estimate because you assume we socialize indoors: dinner parties, movie theaters, and do on.
Assume we socialize outdoors. It helps.
Then you have a counting problem. It's not the masks helping then but the shutdown of that stuff. Those don't count as masks unless you can do them with masks.
With respect to the factories, if you make workers work, they are going to socialize. They aren't robots. Don't you remember Tom Cruise's rant against his crew?
But again, you don't care about the actual real world because you are just preaching. You just want everyone to be virtuous, not who they really are (which would be policy)