Keeping fluids flowing is very important to all of us, with holding can cause problems. Not everyone is effected the same however for flights over a couple of hours dehydration can sneak up on us and cause all kinds of problems either before or after the end of the flight. I guess I feel to look at this realistically, I am not 30 any more and at 62 I have issues to deal with. I do not want to curtail my flying and if an external cath is the way to go so be it. Smart, comfortable and prepared to enjoy another day of blue sky.
Now to find a discreet supplier.