You can lead a horse to water, but you can't make him drink.
Well this horse will drink the water from what the rest of the world drinks, thank you.
If cloth masks were ineffective, then why are they being required nearly everywhere? You can cling to a few articles or studies which support your viewpoint, but if they are being used virtually everywhere in the world, then my hunch is that they are on to something.
The WHO only says they don't recommended medical grade masks, because they should be reserved for healthcare and medical doctors and nurses. They make no mention of cloth masks. The CDC does however.