augean

a. 1. (Class. Myth.) Of or pertaining to Augeus, king of Elis, whose stable contained 3000 oxen, and had not been cleaned for 30 years. Hercules cleansed it in a single day. [ 1913 Webster ]

2. Hence: Exceedingly filthy or corrupt. [ 1913 Webster ]

Augean stable (Fig.), an accumulation of corruption or filth almost beyond the power of man to remedy. [ 1913 Webster ]