All those drain cleaners didn’t work. Pulling the stopper out and cleaning the gunk off a paper towel worked.
I recommend nitrile gloves. Don’t run the tap when you have the lever screw open, water will leak out of there. You can use an old toothbrush to reach down the drain pipe and pull up more gunk. After, I filled the sink up with hot water then drained in one go. Don’t know if it sanitizes exactly but I think it helps, cut down on the smell anyway.
Drain cleaners work from long exposure on a blockage. You wouldn’t want to handle a chemical that could dissolve all that hair and bio buildup by pouring it through a slow drain because if it splashed on your skin it’d burn through your skin in the same time.
Manual removal is always best. If you want to be proactive, get a long test-tube brush and put it down the drain periodically so you don’t have to disassemble the drain.
It’s disgusting, but it’s satisfying to take it apart and give it the old toothbrush like you suggested from time to time.
This is pretty fast, took 15 minutes and I was really cleaning it.