I've tried to hobby in both Naples and Rome and it's very difficult.  Italy is more like the U.S. than Germany, so what's out there is underground and low-key.  In Naples, the best I could do was extras in a strip club for a lot of money.  From what I could gather, most of the hobby is "streetwalkers" around train stations and along highways.  As a matter of fact, my Naples hotel was across a big traffic circle from the rail station.  There were dozens of young, mostly Eastern European girls walking the sidewalks and out in the street.... not a very good scene at all.  I never found brothels, massage parlors, or much of anything.  It was so bad that I was ready to hop a train up to Germany or Spain.

Most of the hobby is in the escort world and there are plenty of sites out there.  The challenge is to separate the real from the fake.  I never got that far, but, perhaps someone else has.