Resource for checking unused CSS, and outputting "clean" file


I know I used a website like this in the past, that will check your css file, and determine what classes/selectors are not used. I do realize dustme selectors does this, but i am looking for something that will OUTPUT the new css with the unused code REMOVED.

Anything coming to mind? I have a style sheet that is huge and it would take forever to go through by hand.