Typically depends on provider preference, how busy they are, and how well you know them.
I would say most showers are included but they count against your time, as it should.
Originally Posted by argus256
. . .only if she is in there with me does it count. Hence, the reason I don't do incall unless I have to. If I know the provider well, and need a shower before heading home, I ask if I can rinse off real quick and I am quick about it and keep her bathroom tidy.
If she is uncomfortable with that, or pressed for time I look for a rest area or stop in a McDonald's restroom (cleanest and most spacious you will find when in a hurry). Another trick of the trade I learned about is if you are a YMCA member, just stop in and clean up on your way home--or actually workout if you choose. Even in a strange city, your card will usually get you in and even if you pay a small guest fee it will be cheaper than counting against your time with a provider.
The other thing to do is look for a park. Some have showers in them (especially if the park has a campground), and once again, at least in this part of the world, the public restrooms are fairly clean and spacious.
Doing outcalls, I always extend the provider as much time as she needs off the clock and full use of my shower and other amenities--ps gents, ask houskeeping for a few extra towels when entertaining guests.