I'm talking about sharing a shower for washing only. Not for sex and not for golden showers.
In my experience:
Around 10% of escorts will refuse because it crosses a boundary so I respect that and leave. (I always discuss this before money changes hands and, as long as the escort has good enough English, over the phone when making an appointment.)
The rest are OK once they understand that they do not have to get their hair or face wet though almost all seem to find it an unusual or even a unique request.
Most escorts have a bath with a shower inside which is way way bigger than you need.
I have never seen a shower stall in Ireland that is too small if you understand the technique.
In a really small shower, you need to wipe some gel over the front of your body as a lube and then hold the lady close to you, facing you. You then reach round and wash her back and then turn her round and reach around and wash her front. The escort then reciprocates. It's great with a really tall escort who has long arms.
About 10% of escorts will, without request or prompting, suck your dick in the shower. Lovely.
If the shower is inside a bath, be a gentleman and make sure that you offer your hand to the lady as she enters and leaves the bath.
After, comes the best part. You towel each other dry. A surprising and pleasing number of escorts have commented to me that they enjoy that.
One escort, not around here but stunningly lovely and with long blond hair was concerned as she had no clip or band to tie up her hair. We had to be extra careful but she didn't get her hair wet. I have learned my lesson and carry a hair clip with me should the need arise. She also made a very perceptive comment:
"This is not just about getting washed is it?"