Green’s Dictionary of Slang

knocking-shop n.

also knocking-crib, knocking-house, knocking ken, knocking school, knock shop
[knock v. (1a) + SE shop/crib n.1 (1)/house n.1 (1)]

1. [mid-17C; mid-19C+] a brothel.

2. [1910s] (Aus.) an untidy or dirty place.