FKK Colosseum in Augsburg
Unfortunately, Munich, Bavaria and the whole Catholic southeast of Germany is a bit of a pooning backwater, at least compared to the rest of Germany. FKK's are the gold standard of sex clubs in Europe and they're just not as good in Munich as they are in and around Frankfurt or further north along the Rhine in Cologne and Dusseldorf.
Fortunately there's an oasis in this desert. It's about 45 minutes west of Munich in the historic town of Augsburg. FKK Colosseum is in an industrial park in the city's northwest, a solid 50 minute walk from the main train station, likely 15 minutes by cab, maybe 20 if you can figure out the fairly straightforward local tram system.
http://www.fkk-colosseum.de
I've been to this place a couple of times and, while it's not as good as the best clubs in the Rhine area, it's pretty solid. About 25-30 ladies most nights, most of them 7's, 8's or better. Mostly Romanian, Hungarian and German girls with the odd exotic Caribbean or Latina in the mix. Similar prices and services to the marquee FKK's. 60 Euro entry, 50 for the half. BBBJ is standard. The club has what they call a no-approach policy meaning you have to start a conversation with the girls. They can't approach you first and they can't hassle you and aggressively hustle the way they sometimes do in the bigger FKK's. The one massive bar-spa-lounge area makes it feel a bit more like a public swimming pool and a bit less like a Roman pleasure palace than the owners intended I think but it's a pleasant, clean place with pretty decent spa facilities. Lousy food though.
A second FKK has recently opened in Augsburg called Cleopatra and I think reports are that it's pretty good too, especially by Bavarian standards.
http://fkk-augsburg-cleopatra.de
I've heard okay reports about FKK Hawaii in Ingolstadt, less than an hour north of Munich, but I've never been.
http://www.fkk-hawaii.de/en/
All those little medieval towns along the Bavarian Romantic Road are well worth visiting for their own sake so you could probably easily justify the day trip.
Lots of information about FKK's here:
http://www.internationalsexguide.info/forum/forumdisplay.php?275-Germany-FKK-Clubs
One last tip. Travel by train and get a day ticket that covers the whole German federated state of Bavaria. It costs 23 Euros and will cover your train to and from Munich as well as all the local trams, busses and subways. Super convenient and economical. You just buy it at the vending machines in the station.
And if you've never been to Munich before it's an incredible city. The whole of Bavaria is terrific.