Even if you brush, floss, and use mouthwash, you still might be cleaning your teeth wrong. Because the order you do them in matters. Most people who do all three brush first, then floss, then use mouthwash. But the right way is the exact opposite of that. Here's the correct order . . . rinse with mouthwash first . . . then floss . . . then brush. If you rinse with mouthwash at the end, it washes away the fluoride from your toothpaste.