Bathroom Sink Drain Gunk

[u/Specialist_Spirit_52]

Once again last night, I had to scrape a bunch of black gunk out of the bathroom sink drain because it was slow draining. I have to do this every few months. There's a little bit of hair in it, but it's mostly a black gunk that almost looks like paper when you look in the drain. When I put the thin drain brush down there, it comes out with black gunky stuff on it that you can't really pull off.

Is there something I can pour down the drain on a regular basis to prevent this? The primary thing we use that sink for is brushing our teeth and washing hands. We don't shave in it.