A 'dirty hurty' is when a person applies faecal matter to a coarse piece of sandpaper (preferably 60 grit) and then goes on to use it as a masturbatory device. the rest is up to the imagination.
"Man, that was a pretty hectic dirty hurty i gave myself last night."
A disgustingly run-down house that has rent so cheap you can't complain. Typically for large groups of college students. Landowner may or may not be the sketchiest guy you know.
Person 1: Man, I don't know what I'm gonna do after highschool.
Person 2: Get a Dirty Herty with me and the gang. We'll figure it out.