Yes you can, with one caveat.
According to Stephen Krashen’s input hypothesis, compelling, comprehensible input is sufficient to acquire a language. That means input that you find interesting and that keeps you engaged, and which you can understand at least in part. That evolving sweet spot can indeed take you from complete newbie to fluency without ever speaking.
In my experience, though, being able to speak with other native speakers is a huge source of motivation and creates its own compelling input. So I wouldn’t discount that.
I personally know someone who went from no English to being able to converse just by watching The Simpsons.
Better to brush after getting up to remove any bacteria and plaque buildup. And then right before bed, floss+brush.