I've seen people talk about how bandanas work just as good as surgical masks.

Here's why that's wrong:

On the left you can see cotton fiber (used for bandanas and such) under a microscope, on the right you can see fleece fiber, which is used for surgical masks.

It's clear to see that the cotton fibers naturall contain little holes, which is enough to let aerosols escape through them. The fleece is not fabric, it's molten polymere (plastic) which means that most holes are closed.

The left picture shows a person coughing through a cotton mask. The right person is coughing through a fleece mask.

Please choose surgical masks, or even better N95 masks. Be safe.