R, Mel,
I think it is almost entertaining to read all the variations of prep advice we all got (or didn't get). OK, no it is not at all. It is scary.
My clinic had signs on the wall and a big water cooler. Signs like "Got water? Had it long? No? Tell the receptionist to let the next guy go first!" or "500 ML 45 minutes before - drink up!".
Every appointment card and piece of collateral paperwork had something of the like printed on the top, bottom, or sides.
My poor bladder would not (and still won't) hold that much, so there were a few trips to the car detail shop for seat shampoos, and it did take a while to get the time right.
The techs were all interested in the stories I passed on from HW. Maybe it was Squid who was using the new (at the time) daily CT? They said that was bleeding edge technology, but there weren't any in my area. Pity that the clinics had finally just ramped up with the latest of the previous generation, so none had the money for the latest latest.