1. The unsuspecting woman agreed to invest all her money with an unethical investment banker. He took her to the cleaners , and she was left without a penny to her name.
2. I made the mistake of giving my dishonest nephew a blank check from my bank account. Instead of writing it for the amount we had agreed on, he wrote it for every cent I had. He took me to the cleaners.

Synonym: clean (someone) out.