This is what I cannot understand.
Im sure there are numerous ways all you gals use to get wet, or to CONTINUE to get wet when working - especially on a long term basis! (or if you are purely doing it for the money instead of a kind of emotional satisfaction)

*Imagining its someone REALLY HOT, celebrity or a person you know/knew
*Applying lube in the bathroom beforehand
*...Can't think of any others lol - maybe a combination of the 2?

Apart from the excitement you might get from doing this job..or not, I don't see how it can't be a problem.
e.g. Chafing
or maybe guys usually come quickly out of anticipation? lol

P.S. Am V small too! Can only take 6 inch penis - is this a problem? Not just for getting wet.. but in general while working with men of all shapes and sizez.. cant imagine them being very happy if theyre 7 inches and cant put it all in without it hurting lol