Milk/suck somebody/something dry
Definition 1 of 2
Pro Tip 1/3Metaphorical Use
The phrase often represents draining resources or advantages, not just money. 
Uncontrolled tourism might milk the island's natural beauty dry.
Pro Tip 2/3Negative Connotation
Implies a selfish or harmful intention behind the action. 
Venture capitalists were accused of milking the startup dry.
Pro Tip 3/3Idiomatic Nature
It's an idiom, meaning it shouldn't be taken for its literal sense. 
The new manager is said to milk the budget dry in his previous company.