The great thing about cash is you can use it everywhere, not just for things you want to keep on the down low.

You take that fat stack of bills you made selling dime bags and you go to Walmart and you buy groceries with it or whatever. Only the things that require a non-cash method of payment need to involve the banking system. Even then you can buy prepaid visa gift cards to handle most of those case if you're ok with the inconvenience.