A brothel or massage parlour would be a good avenue to launder money.
Claim the cash were the proceeds of the sex business, inflate the number of customers per day, and voilà!! dirty cash turned into clean, and who's going to check the numbers of customers walking in and out?
Tax office does not care, as long as they can tax that transformed cash.
Not saying it happens everywhere, you'd be naive to think it has not happened,