He was filled with 'the milk of human kindness'. [=he was filled with kindness; he was very kind]
They 'milked' [='exploited'] their advantage for all it was worth.
greedy landlords 'milking' their tenants of all their money
(..) ...it courses through the natural gates and alleys of the body, and with a sudden vigour... ...it doth posset and curd, like acid dropping into milk, the thin and wholesome blood So did it mine. And soon a foul eruption barked about, most leper-like... ...with vile and loathsome crust, (..)2015 Hamlet