wrote in message ...
every 20 years, or less,
you should pull the pipes under the sink apart,
and manually clean them out.

The snake thing is only a temporary fix, from my experience

marc

Ditto to that. I replaced a bathroom sink after about 20 years, and the horizontal drain pipe was caked with about 1/2-inch of packed solids. In my case, cleaning it out was really easy to do. Until then, it was always backing up. Now it's been a year and still flows freely.