I usually except the offer of a shower, it'll give you a couple of minutes to chill and it also reassures the wg you're very clean. She's more likely to offer more services knowing you're squeaky clean. I usually come out wearing the towel, I certainly wouldn't put clothes back on, that would be odd.
+1 to that, especially the girl's level of service once they know you're clean and fresh. These days, I always take a shower if it's available or offered, two or three minutes is all you need to take. If it's an en suite shower, I come out naked with a lazy lob on which seems to give them a clue that I'd rather get into it than chat or have a massage. If it's a separate bathroom, towel wrapped round me to get to the room.
Enjoy. You're paying. It's your time. If a WG wants to dock you time for it, don't see her again. A Good Girl will start the clock when you're out of the shower and in the bedroom together, as long as you don't take the piss like washing your hair, clipping your toenails, loofahing your back and such.
Oh yeah, and if there's mouthwash available, use it.