There are plenty of ways to launder money, but they all require work, which criminals usually avoid. Which is why criminals are often found in penitentiaries. Regardless, if you don't want to open a coin operated laundromat (which would be my #1 choice) here are some other options....1) Do what everybody with cash does: buy a dilapidated house on a mortgage. Refurbish the house by paying for parts and labour in cash. Wait a year. Sell the house. Pay your capital gains tax on the "profits" with the relevant tax authorities. The profits are now clean and bleached. Repeat as needed, or until such time as the laundry is done.2) Fly to Hong Kong, deposit your funds with your friendly Hong Kong banker in a commercial account. Buy hard goods in China. Ship them to your place of business at a reasonable profit. Sell the goods. Pay your taxes on your profits. Laundry is done when you are no longer profitable. 3) Buy a restaurant. Make sure your bills are lightly covered in flour, before you deposit them at the local bank. File your taxes on time. Pay the taxes on the profit. Sell the business for book value or find somebody else with a laundry problem at 3X Ebitda. Don't get greedy, those that pay 3-5 times Ebitda for a restaurant know the difference between a wise ass and a wise guy. 4) Buy gold from gold brokers. Re-cast it so the serial numbers are gone. Wait for grandma to die. Make sure she leaves you her favorite chest of drawers in the her will. Take possession of said furniture. Claim you found the gold stashed behind the drawers. File your inheritance tax form with the tax authorities. Make sure you pay off all your relatives, in case they decide to contest the will.5) Start a diamond business. Wash, dry, repeat.SOME OBSERVATIONS:Untaxed money is useless. You cannot spend it and you cannot invest it. "Illegal cash" implies that the law was broken in acquiring the cash. All criminals are eventually caught, on one charge or another. Or another criminal shoots the offending criminal first. If not paying your taxes on legal profits is the end game, you are as dumb as a stump and I don't see how you could have made the money in the first place. There are plenty of legal ways to postpone and finesse the payment of taxes on profitable operations. Universities put out accountants by the hundreds of thousands, and they have certifying bodies, that can vouch for their competencies.