He seems to have written his memoirs mainly so that he can 'dish the dirt' on all his former lovers.
The police 'struck pay dirt' when a witness came forward with new information.
The band 'hit pay dirt' [=had a big success] with their first single.
(..) If you ever need one, I know a fellow who can get you a real nice deal. Lots of shit around. I never use mine. I'm conservative. But it's a good thing to have just as a threat. I'm gonna go do my dirt. Travis. Look. A piece of Errol Flynn's bathtub. Dig the symbols. "F- -----" (..)1976 Taxi Driver