What is the Mandarin equivalent for the Shanghai term for dirty? In the Shanghai dialect dirty is pronounced something like "o co" with the o pronounced like the "o" in cot and the "c" pronounced like the usual c in pinyin (kinda like an 'ts' sound).

Which characters would be used for writing these two?
龌龊  wò chuò
Meanings:
(1) dirty；filthy
(2) mean,despicable

It's not Shanghai dialect only. It's used a lot in northern China as well.