This will only make sense IF your expenditure is in USD, but you have to keep your capital in EUR - otherwise you will incur RISK for this 2.5% something return -> so it won't be a freebie.
Assume I have X amount of USD as my capital. I convert X to EUR, and get Y EUR. Then on a broker with good swap rates, I sell Y EUR. Then Invest Y EUR however I wish - and on a monthly basis, readjust my SELL Y EUR position for new Y (my current capital amount in EUR).
That makes sense? Please keep in mind that, if the "Spend USD, gotta keep money in EUR" is NOT true, the risk is probably not worth it.