We tend to think of the divine spirit in terms of radiance, but it encompasses all things, including the polluted, filthy and vile.
Yes, zen can be found even in the toilet.
A monk once asked the zen master Ummon, "What is Buddha?"
The reply came, "A shit stick!"
The monk was shocked by the master's vulgarity. But Ummon's message was that all things speak of God, even soiled toilet paper. We may think of bodily waste as dirty, and yet it feeds the ground as fertilizer.
— Philip Toshio Sudo, Zen 24/7