I suppose we can also add Edinburgh (although it’s not a hub). Get the airport Airlink bus from right outside the terminal (not the tram), 30 minutes to Waverley, from which it's about a 5-minute walk to BSS. There’s a slight concern that you might arrive when all the girls are busy but that’s fairly unusual. You could phone ahead from the airport bus and reserve. The bus costs £7.50 for a return journey. If you prefer Newtown Sauna, the tram terminates at York Place and the sauna is less than 5 minutes walk. A return ticket on the tram (buy from the machine before getting on) costs £8.50 and the journey’s 40 minutes. It’s a few more yards to walk from the airport exit than the bus.
It seems to me every airport should have the facility.
Many hubs simply don’t — virtually an absence of punting altogether (CDG and almost all American airports) or else the opportunities are simply too far away (most S.A. airports) or too much hassle (Sydney, Dubai).
Who knows how long it would take in a layover from Madrid, Beijing, KL, Bangkok, Heathrow?