Lots of peeps do it. It's not that hard to do. One could simply bounce it from one country to another, set up a business, and a bunch of other things. You don't need to be a billionaire to do it.

If you decide to put your fiat money in the system, it's already clean by then, and if you put it to work earning dividends, then you are paying taxes on that income, the government will likely not go after you. They have bigger fish to fry.