Dad! Fantastic avatar.
agree with Jay.
When I talk to the mamasan on the phone I always find out how many girls are working (it's almost always two) If I'm not crazy about the look of the girl who answers the door, i'll ask to see the other girl. The door girl will pretend she doesn't know what you are talking about, but if she is enough "not your type" then it is your perogative to request at least a look at the other girl (if not in session). It is your hard-earned money you should feel as though you are spending it as you wish. I've even left a place or two after neither girl met my standards.
All that said, the AMP talent has been very reliable in the last year or so, and I've pretty much been able to go with the door girl lately.
Also, a shower isn't required. I typically shower right before a session anyway (which I mention to the girl) and I always make sure she knows I've washed my hands before our session. But AMP gals are known for their attention to hygene. So if in doubt, take the quick shower--your session will probably only last 30, maybe 40 minutes, so it's not like a quick shower will kill your schedule.
Have fun. Post a review.