The twists and permutations some will make and take to save $50 or so is quite something, especially when the downside if something goes awry is not insubstantial. But back to the OP specifically? Kosher? No. Halal? Also no. Against the law? No. Against the T&C of the ticket you purchased and refunded along with the airline's general COC? Maybe.

On the the other hand, the opportunity to travel to, say, SFO, and pay a dollar every few minutes for parking, or no less than a near $20 BART fare in/out of the airport for the opportunity to eat on the finest of disposable china and drink out of the one-use crystal and eat a buffay of things so rare, you might only find them at Safeway, for "free," no less during a lounge visit, is priceless, or damn close to it!