"Shit stick means "a thin stake or stick used instead of toilet paper" and was a historical item of material culture introduced through Chinese Buddhism and Japanese Buddhism. A well-known example is gānshǐjué/kanshiketsu (lit. 乾屎橛 "dry shit stick") from the Chan/Zen gōng'àn/kōan in which a monk asked "What is Buddha?" and Master Yunmen/Unmon answered "A dry shit stick".
"The English language has some shit(e) stick lexical parallels to these Asian language terms. The Oxford English Dictionary (s.v. shit, shite n.) quotes two early shit-stick examples: "a hard chuffe, a shite-sticks" (1598) and "a shite-sticks, a shite-rags, that is to say, a miserable pinch-pennie" (1659); and (s.v. poop n.2) defines poop-stick as "a fool, ineffectual person", with the earliest usage in 1930."