Absolutely. Specially convenient if you had a red eye flight and then a long layover. You can use the shower snd start the day refreshed.
Yes
The general rule is that an airline will allow you to use their club provided the segment you will be boarding next is first class or business. If only the prior segment is first or business, they will not allow it. However, having said that, many do allow entry via a daily fee, or if you have a gold or platinum credit card from the airline - please consult with the respective airline credit card company for details on their specific deals, as different conditions apply.
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