One of the preliminary processes preparatory to tanning. After bating or drenching the excess fermenting materials, together with dirt, fatty matter, hair follicles, short hairs, and glandular tissue, are worked out of the hide or skin. (11) Mostly done by hand using a blunt two-handed knife over a curved beam. Can be done by machine.
Found on https://www.encyclo.co.uk/local/20861