Green’s Dictionary of Slang

(US) usu. in pl., a sock.

1928		M.C. Sharpe Chicago May: Her Story in Hamilton (1952) 132: Oscar Hocks – socks.
1944		Maurer & Baker ‘“Aus.” Rhyming Argot’ in AS XIX:3.
1953		Berrey & Van den Bark Amer. Thes. Sl. (2nd edn).
1966		M. Braly It’s Cold Out There (2005) 190: He thought of the Sock Man passing the cells [...] calling ‘Oscar Hocks, Oscar Hocks.’.
1999		E. Bunker Mr Blue 114: ‘Oscar Hocks’ are socks.