Earlier quoted context omitted.
If he meant that "cloth masks aren't good enough " he could have said that. But he's a senator. His statement was a dog whistle to his base. They're not looking for an argument that people should be wearing N95s, they want to discredit all masking. The word "prevent" is a red herring -- nothing is 100% -- the goal is to decrease infection, not prevent it.
This whole dog whistle thing is just a way to put whatever interpretation on someone's words you feel like.
They’re not hard to identify if you understand the viewpoints of the listeners or even just observe their reactions. If two groups like a statement, but they both thought it meant a different thing, that’s probably a dog whistle.
Take for instance:
“Vote for kube-system, he’s one of us. He thinks congress should do what’s right for Americans and their families; end the dishonesty in Washington, and protect the rights and values you deserve.”
What demographic am I talking to? Who are the dishonest politicians? What rights and values? Could be anyone!