Germany did the same study and came to same results. Those fabric masks are still only 3% - 10% effective, eg pretty useless against the main infections, 1. direct aerosol via the nose, 2. hand to eye, but even those little numbers sum up in the exponential growth scenario.

They help against flyby droplet infections, help a bit against the aerosol load, and they prevent touching your eyes a bit. Removing caughers and washing your hand is still much more effective though.

And btw. the "second wave" will come for certain in the fall, but it will be another uncertain mix of influenza viri. Vaccination is always a gamble, because you never know what will come. 2018 it didn't work out, with the same numbers or worldwide much higher numbers as 2020.