I'm a very hygienic person in most aspects of my life. I shower every day (occasionally every two days if I don't get dirty or sweaty), I wash my hands on a regular basis, I never use clothes more than once without washing them.
The only thing I don't clean is my teeth. For some reason I can't make myself do it. I brush once every few weeks. Yes, my teeth are full of cavities. No, I don't plan on changing my habits.