I will also post on UA and NH boards.

I am arriving in first class on an ANA aircraft but ticketed as UA. ANA, upon departure, uses the BA lounge at JFK. I would like to have access to the showers (they do exist, right?) upon arrival at JFK.

If the showers are indeed open, can I ask ANA to allow me back in through security so this can be done?

Has anyone upon arrival at JFK ever tried to get back into the lounges?