https://travel.stackexchange.com/q/90413/4188 

I've been that passenger several times, typically on connecting flights after a transoceanic leg. I really try hard to find time and place to shower after such a flight (you can see it in my post history here and on flyertalk) but it's just not always possible. For example, the queue for the shower at the KLM Lounge in Schiphol in the morning is too long. So what can be done if a shower is not available?