Spoilsport
Along a similar line, I couldn’t recommend sprinkler showering nowadays, as many of our parks are now (hurray!) irrigated with reclaimed water. You can tell by looking for the purple pipes/spigots.
Good god, if you’re that cheap, just wait until you get home.
I’ve road tripped around Europe a few times and done this a lot. I’ve found the best option for a real shower is to walk onto a campsite like you belong there. Campsites never have checks to see who is staying there,* and the showers are always open. If you’re lucky they’ll even have hairdryers.
If it was a nice, small, family-run campsite we would ask to pay a little to use the showers. They almost always let us for free.
Sometimes hotels have showers in the loos in the lobby, and they also often have showers in the changing rooms for employees. Again, just walk in like you belong there. The biggest problem is that you can’t walk in 7 people together with a towels and sponge bags, which you can at a campsite.
We had those camping showers, and found the best thing is to wipe down well with a Wet Wipe and then rinse that off. We tend to be a big group, so the shower doesn’t hold enough water for everyone to actually shower. But wiping down and then rinsing off makes you pretty clean. I don’t like being left with that Wet Wipe film, I feel that needs to be rinsed off.
*Except for one in Italy, where a security guard chased us. It was quite terrifying!
Boy, you’re picky for a freeloader.
At Incheon they are in the secure side of the airport, available only to passengers with a boarding pass or connecting flight. And they weren’t cheap. I don’t remember how much, but I decided to stay stinky.
Same with Bangkok’s Suvarnabhumi Airport, and just about every other airport I’ve seen that offers shower facilities.
Bar of soap, swimming trunks and a lake or river?
Presumably you’ll be staying someplace in the city the night after the hiking – wouldn’t you be able to shower there?
I showered at Incheon in December. It was free.
Gitchyseff some of these Athletic Body Wipes. Read the reviews. People use them to freshen up when they bike to work and really love them. They’re 8"X9", bigger than Wet Wipes.
Re the college gym: try a small community college not a big university. Once I had a concert at night and nowhere to change, so I just walked into the women’s locker room/gym at the downtown community college where we performed. It was about 6 pm. Only a couple of other women were in there and no one asked for ID or anything. I’m also a LOT older than college student age, but no one even noticed me. At that time of day, people just want to get outta there and get home. This was about six years ago.
There’s no way you could do this at the Y or a University in my town. It’s pretty tightly monitored.
This would work but the water pressure is a bit harsh; plus being clean but covered in delousing isn’t much better than being dirty. 
I think this is probably a pretty good idea. A lawyer friend of mine uses couchsurfing all the time. He’s stayed in homes all over the planet.
I like the idea of finding a parks & rec gym. At least the ones around here aren’t monitored too closely; but finding one with shower facilities might be a challenge. Of the three city parks in my town that also have a gymnasium, I think only one of those has a shower facility.
Personally, I like the idea of the whore’s bath. If you carry a washcloth and soap, you can get pretty clean from a sink. If you’re Jack Reacher, you could throw your old clothes away after you buy a new set from the thrift store. Just make sure you hang on to your toothbrush for your back pocket.
Both universities I’ve been affiliated with have the occasional (seemingly) random bathroom on campus that has a shower in it. Both of the ones I’m thinking of are in engineering buildings… Anyway, those buildings are open to the public (unlike dorms or rec centers). I suspect you’d have to be pretty familiar with the area to know about them, though.
This is quite easy. Check into a slightly, but not too sleazy motel or hotel. Take a very quick shower. Take all your stuff and tell the front desk you saw a roach/rat, etc., and that you are leaving. Demand your money back, then leave. Tada!
Water sitting in a steel pipe for years would not be bacterially infested. There is nothing for bacteria to live on.
Up until the mid 70’s, both Paris (France) and Melbourne (Aus) still had public baths – that is, places where you went to have a bath if you were living in housing without a bath or shower. I assume that every old city used to have something like that, but I’ve no idea how long they lasted in other places.
If you know your way around, it’s often the case that a “homeless shelter” includes shower facilities. I used to know where to go to get a cheap shower in Melbourne, but I live in the outer suburbs now, and I don’t mix in those circles. All of the places I knew, I would have felt uncomfortable staying the night (they were pretty tough), but I would have felt safe having a shower.
The universities around here would be locked up too tight. The hospitals in the city, near the shelters, would be locked up too tight. But the hospital out here, if you knew your way around, you could scrub up where the fathers-to-be scrub up before witnessing the miracle of birth.
Now, reference the THREADSPOTTING title:
“There must be 50 ways to get a shower.”
– 50 ways to get a shower…
Y’just slip in the dorm, Norm…
Speaking from experience … Marina’s are where you can take a shower on week-ends on the west coast. Just stand outside the men’s or women’s restroom shifting your body weight around like you have to go to the bathroom real bad, carry the soap and or shampoo in your pocket or yacht looking hoodie (just one of those small hotel shampoo bottles works for me).
No change of clothes or towel and once inside, due to some nice person going in or holding the door for you that was going out, you can scope out the situation and act like you are a yacht owner. Go boldly for the shower stalls usually in the back.
Get in and get out … no dawdling, do not tarry and leave abruptly headed back to the parking lot or just a park bench if that’s all you have. Brush your hair and rest in the sunshine.
Good luck I only got arrested once in two years down San Diego way and the security guard let me go on that one, but I did not return of course.
Anecdote: I was helping my father move out of his (sketchy) apartment and while he was packing stuff up in the bedroom I got a glass of water from the kitchen sink. I had to wiggle the faucet a bit but it worked. He came out and informed me he hadn’t been able to get it to work for years. I didn’t get sick.