Quick update. I used the arrivals lounge for a shower this past Saturday, connecting from DEL to JFK. I arrived from DEL at 5:15 am at a D Gate. I was in the arrivals lounge by 5:30 am and back in the business class lounge by 6:20. I was literally the only customer in the arrivals lounge. The shower rooms are larger than the departure lounge, have a better luggage/changing area and, of course, no wait. This is the way to do it if you want a shower between flights.