Its weird, in over 20 girls during the years i never had any probs in that departement, but then again i don't go down on them.... Maybe if i got really close it would had been different but this something i don't do. Also 70% of the ones i saw, i was first client of the day, wich i think help both a better meeting in term of attitude(she aint tired of her day) and cleaness.
As for the peeing on the bowl, yeah this may happen, but usually they shower after or they clean themselves... i mean personally i make sure to not pee after my shower, or i should say make sure i do BEFORE so it dosen't happen during the meeting. If they keep talking to you like nothing its probably because they think you just had sex with them, saw them naked and such, so its no biggie to see them pee... Personally i prefer if she close the door yeah... but if she don't then well, i won't hold it on her ...