Originally Posted by
Often1
It is no unethical, it is ticketing fraud and directly violates DL's COC.
While it is fraudulent in general (buying a ticket you never intend to use), there is nothing in DL's COC about this. AA on the other hand specifically prohibits the purchase of tickets solely to access airport facilities etc.
An alternative would be to ask for a gate pass. DL is particularly easy about these and you then don't have to spend time afterwards fixing things.
Can't imagine a gate pass would get you into the SkyClub.