While we do pull the hair out of our brush every so often, we have to admit it's unlikely we'll actually clean it.
But, according to one woman, we should be washing our hairbrushes every two weeks to keep them free of any build up.
In a clip that's currently going viral on TikTok, user Jessica Haizman shared what happened when she gave her hairbrushes a 30-minute "bath" in the sink, and the results are pretty grim.
"Ever cleaned your hairbrushes?" she begins in the video demonstration. "Realistically you’re supposed to clean your hairbrushes once every two weeks."
She goes on to explain how she went about cleaning her hairbrush.
"I started by pulling out as much hair as I could and then I gave them a bath,’ she says.
She put the brushes in the sink, filled it with water and added baking soda and shampoo, before rubbing the mixture into the brushes and letting them soak for 30 minutes.
When she returned, the rust-coloured water was full of grime.
Haizman added that she doesn’t use hair dye or much product in her hair so the grime hasn’t come from that.
She ended by rinsing each brush "really well" and letting them air dry thoroughly by laying each brush flat on a dry towel.
While some viewers of the clip praised Haizman for raising awareness about the importance of hairbrush cleaning, others said they've always been aware that brushes need washing.
"Wait, wait, hold on!! You mean to tell me people don't do this every day?" one TikTok user wrote.
Another said that while she replaces her brushes every year, in between she uses a little bit of shampoo and a toothbrush to clean them before rinsing.
Watch: Coco-Cola cleaning hacks you need to know about.
How often should we be cleaning our hairbrushes?
If, like us, you're a little grossed out by this hairbrush washing revelation, the good news is your grubby brush probably won't do too much harm, but it does serve as a wake-up call for upping the ante on how often you clean them.
Haizman is correct that we should be cleaning our hairbrushes regularly. According to Lisa Caddy, trichologist at Philip Kingsley we should be cleaning them once or twice a month.
That's because styling products, dirt, dust and oils can accumulate on your brush and, when you style, they can transfer back onto the hair and weigh it down.
And you really don't want to be brushing old products, dirt and maybe even dead skin cells back into your hair and scalp when styling, particularly if you've got freshly washed locks.
Caddy suggests we should be removing loose strands from our hairbrush after each use especially if you have long hair.
"If you don’t, these get wrapped around the brush and become much harder to pull out later," she explains.
"Trapped hairs also make it easier for styling products to stick to the brush meaning you’re brushing that back onto your hair."
On a weekly basis, Caddy says we should use a comb or a soft brush to completely remove all hairs trapped in the bristles.
"Then, a couple of times each month give your brush a deep clean with soapy water," she adds. "Take care with wooden brushes, don’t soak them or they will damage.
"If you use a lot of styling products, hairspray in particular, you’ll definitely need to do this twice a month. A build up of sticky products attracts dust and dead skin cells which will make the hair look dull."
The trichologists at Philip Kingsley suggest first using the skinny end of a comb to remove the hair strands from the brush before giving them a wash using warm water with a mild detergent (i.e. soap or a small amount of shampoo).
Let them soak for 15 minutes before rinsing and allowing to dry.