They usually make it so you can’t cash out anything that’s less than the voucher. Or rather that the wins get counted first.
Let’s say you get $50 free, win $25. You then play for $25 and lose, the remaining $25 shown on your balance won’t be able to be cashed out.
Do your landlords not have any requirements to provide even a communal washing machine? In Sweden, and probably most other countries, the law says you have to have it within reasonable distance, otherwise the apartment isn’t considered “livable”.