pure finder

Wiktionary

1. n. obsolete Someone who collected dog faeces for sale to tanneries (which used it as a siccative for bookbinding leather). Undertaken by old women in Britain in the 18th century. (Reference: Robert Hughes, The Fatal Shore, 1987, paperback 1996 ISBN 1-86046-150-6 chapter 1 page 21.)
2. n. Used other than as an idiom: see pure,‎ finder.