In any painting , carpentry, or similar type of ajob, Dick-Strip refers to a long thin area or space or bit of lumber that is difficult to reach or work on.
Boss: Hey, man! Did you paint that little dick-strip on the back porch?
Worker 1: No worries! I got it.
when you are doin your girl from behind and you proceed to blow your load up her ass, take two fingers in a hookfashion pull some of your man juice out and wipe it across her teeth like a crezt whitening strip hence the definition cezt whitening strip.