My daily hairbrush had a layer of grayish gunk at the base of the bristles that I had been pretending not to see. Then one morning I looked at it in good light and nearly dropped it. That is not hair, I said out loud. That is a museum exhibit.

Here is the good news: a hairbrush collects oil, product, dead skin, and dust no matter how clean your hair is. It happens to everyone. And cleaning it takes about five minutes with stuff you already own.

What you need

Just a bowl of warm water, a few drops of shampoo (or dish soap), and an old toothbrush. If the brush is really bad, add a spoon of baking soda to the water.

The five minute routine

1. Pull the loose hair out first. I use the tail of a comb to lift it, but your fingers work fine.
2. Swirl the brush in the soapy water, bristles down, and let it soak for a couple of minutes.
3. Scrub between the bristles with the toothbrush. This is where the gunk lives.
4. Rinse under running water, bristles down so water does not pool in the base.
5. Lay it on a towel, bristles down, and let it dry overnight.

The first time I did this, the water turned a color I will not describe in detail. The brush came out looking brand new, which was honestly alarming because it meant I had been brushing my hair with a petri dish.

Two warnings

Do not soak wooden brushes. The wood will swell and crack. For those, wipe the bristles with a soapy cloth instead of dunking the whole brush.

Do not use boiling water. Hot tap water is plenty. Boiling can melt the glue holding the bristles in, and then your brush falls apart mid hairstyle.

I clean my brushes every two weeks now, and I have a reminder on my phone. It takes longer to find the toothbrush than it does to do the actual job.