Lately, many of us have been paying close attention to our hand-washing methods. Everyone knows to wash with water and soap, but actual techniques vary. Some people may suds-up for a simple 20 seconds, while others may opt to sing “Happy Birthday” twice.

What’s the best method? Reddit has some answers. Recently a user posted a graphic exposing bacteria on hands after different kinds of washing techniques.

The importance of washing your hands properly. The parts that glow under a blacklight are dirty. from r/interestingasfuck

The comparison is derived from a 2015 Daily Mail article, where the author used “Glo Germ,” a product that simulates how bacteria clings to your skin under a UV light. So what’s the verdict here?

Well, for one thing, the “wash and shake” method really isn’t cutting it. So just don’t do that ever again. And while a good 20 seconds may leave your hands relatively germ free, it’s probably better to try for an athletic 30 seconds — just to be safe.

Still, according to the CDC, “at least” 20 seconds will do if you’re in a rush. Here’s their official hand-washing recommendations, via Digg:

1. Wet your hands with clean, running water (warm or cold), turn off the tap, and apply soap.

2. Lather your hands by rubbing them together with the soap. Lather the backs of your hands, between your fingers, and under your nails.

3. Scrub your hands for at least 20 seconds. Need a timer? Hum the “Happy Birthday” song from beginning to end twice.

4. Rinse your hands well under clean, running water.

5. Dry your hands using a clean towel or air dry them.

Happy Birthday

Here’s what haunts me about singing while you wash: Do you sing Happy Birthday to yourself while washing your hands? Isn’t that awkward?

Awkward or not, one Twitter user did us a great service. “I’m tired of singing Happy Birthday and you probably are too,” Jenn Monnier tweeted. “So I’ve done the very important public service of compiling other songs with roughly 20 sec choruses to sing.”

Monnier highlighted the choruses from “Love on Top” (Beyonce), “Landslide” (Fleetwood Mac), “Raspberry Beret” (Prince), “Jolene” (Dolly Parton), “Africa” (Toto) and “Truth Hurts” (Lizzo) as alternative hand-washing tunes.

Watch this