The hand that you used when you went to a friend or relatives' house, took a huge crap in their toilet, and in fear of clogging it, shoved your hand into the bowl to break down the huge turd into smaller, flushable peices. This hand becomes your "Shit Claw" and, no matter how much you wash it, will smell for hours.
Guy1: Ughh, dude, whats that smell??
Guy2: Oh, thats my shit claw, I just came back from visiting my cousin's mansion.
Guy1: oh, thats understandable, but dude, that shit smells.