Most money laundering happens in US, UK, and EU with high street banks. The biggest money laundering cases in recent years have involved banks like HSBC, Deutsche Bank, and Standard Chartered.
With secrecy largely gone and offshore banks in particular having little to no risk appetite, offshore banking is mainly about wealth management, diversification of assets/risks, accessing different markets/currencies, or conducting regional business.
If you're looking for how to launder money, this isn't the place.