Same concept as car wash, nail salon, hair salon, anything that ends in salon or spa or massage parlor, laundromat, or similar legitimate business. Any service provided by a business that will make you clean. Or will clean your possessions. Can also clean your money. Many comments in this thread explain the rest of the details. But basically cash in-cash out. Pay cash for something legal with illegal money. Business accounts for it. Edit: just had to add that this can be done quicker and easier with fewer transactions of higher value.
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