The dishwasher can't wash that away

Tell him/her to piss off. I can't stand when my roomies don't clean after themselves.

Oh but there is..

I've heard that a brick (or any other suitably solid object) to the head works well as a cure... Note: May need to be applied repeatedly to cure stubborn cases. Side effect may include a large bloody mess and jail time.

This is what happens when people try to be nice!

Well there is.... It's just that those with common sense must suffer those who lack it.

If you don't clean it through once a month than it can become unsanitary from all the food bacterias that can get trapped. But other then that it sounds like OP's roommate just has no common sense.

Problem is if you throw out her dishes, she'd probably use everyone else's dishes and do the same thing.

I did that to my brother once, I came home to find the dirty dishes on my bed instead

How do you keep dishes Esperanto?

Autocorrect xD

But what was your original word meant to be?!

Separate maybe?