I've got some half used cans of latex paint that I need to dispose of. I checked our area's household hazardous waste website, and it says to just open the can and let it dry out and throw it out with the trash. That's fine for cans that are nearly empty, but I've got a couple that are half full (should have bought the quarts!)

Should I dump them down the drain? Paint obviously goes down the drain when I'm cleaning my brushes, but there's something about dumping that quantity of paint down the drain that seems wrong. If I just open the lid and wait for it to dry, how long would it take? Maybe if I stir it every few days?

I checked Habitat for Humanity, and they only take unopened cans of paint.