A guy was on Irish radio and he said he bought the cheapest outbound ticket he could find. Managed to get to the arrivals lounge and find his bag there.
The slightly cheaper tactic may be to actually to buy a fully refundable fare (usually for thousands) for much later in the day, and then cancel it and ask for a full refund.
Fully refundable tickets are awesome. My old company had a contract where all international business travels to customer sites must purchase fully refundable business class tickets. I remember someone had to cancel their travel just before boarding, and the airline refunded everything no questions asked.