Those Who Head for the Moon Find Me

Last week's riddle:

I am largest when closed
Smallest when drawn
Lovely when pooled
Helpful from dark till dawn

Answer: drapery; another shout-out to Leslie.

Though I liked "eyelids" and am ever-open to alternative answers.




And now, this week's: 

Those who head for the moon find me,
But are always quick to leave.
I am stinky, dirty, holey
Yet once vital for reprieve.