Where does the laundering come into it? If the machine pays out in cash and you just walk away with it, you've gone from having a big pile of dirty money to having a slightly smaller pile of dirty money. You could declare that the smaller pile is all gambling winnings (off of a low base), but as soon as that gets audited you have to refer the auditor to the casino's security cameras and there you are spending a lot more than you got back.
You could ask the casino to make a formal declaration that your smaller pile of money is gambling winnings (maybe it's chips!), but why should they lie for you?
And if it is chips, you had to buy chips originally. How do you explain how you afforded those chips?
What's the part of this scheme that works?