worm dirt
n.— «The neighbor boys next door were chewing this stuff that they called “worm dirt.” Of course I wanted to try some. I took about half a handful and swallowed it all. Come to find out I had just swallowed half a handful of Copenhagen tobacco! I was sick for a whole week.» —“Less Than Relaxing” by Heidi McCombs Seattle Times (Wash.) June 7, 1992. (source: Double-Tongued Dictionary)
Further reading
Paul in Batavia, New York, recommends The Door-to-Door Bookstore (Bookshop|Amazon), a novel by Carston Henn, translated from German by Melody Shaw, which includes a wonderful description of a book with a perfect final paragraph that you nevertheless...