Green’s Dictionary of Slang

grind joint n.2

also grind house
[grind v. (1a) + joint n. (3b)/house n.1 (1)]

(US) a brothel.

[US](con. 1964–8) J. Ellroy Cold Six Thousand 317: Grind joints next — bedroom mounts [...] Let’s buy Vegas. Let’s cull dirt. Let’s extort.