Even if you could, chances are you will not be granted access for payment as the lounges are regularly full. A few weeks ago I heard a lady who was trying to pay in and being turned away for that very reason. Hearing the discussion, I asked if I could bring the lady in as my guest, and the receptionist was happy to allow it. I felt happy as I made someone's day a lot better. And of course there were seats available in the lounge once inside.