The act of pooping in the shower, then using ones big toe to rub the larger particles against the metal grate at the bottom to get the chunks through the drain.
The other day after I had already gotten in the shower, a sever case of abdominal cramps hit me. Fearing wetting the floor,making the transition from shower to toilet, or toilet paper sticking to my rear, I squatted down and released my bowls into the shower.
Due to the fact the night before I had peanuts and corn for dinner there was an abundance of particulate that were to big to breach the metal grate to the drain. I used my big toe and rubbed the corn and peanuts against the metal screen using it like a cheese grader until the pieces were small enough to get through!
During the act of oral sex, the female proceeds by sucking on the males penis at the same time, slightly biting down, adding teeth to the act, thus imitating the cheese grading effect. It is not the most comfortable feeling, however, what ever tickles your fancy!