In Munich there is a "Sperrbezirk" forbidden zone (
here is a map of it, caution: HUUUUUGE 90 MiB PDF!).
In this red-orange tinted zone "prostitution" does not start at "penis enters vagina" but at "touching a human female breast for money", it constitutes a crime with a fee from four digits € onwards.
Around the train station area, there are CCTV cameras and at times these are used. You may reckon that the police have some other tasks to do to provide security for the octoberfest, but you may not be sure. Just notice the (relative) absence of of beggars, junkies and street hookers (compared to other cities) and do your math.
There are strip shows in the city and brothels in the outskirts, but at oktoberfest times, services are minimized and prices are maximized.
So either you will lose an awful amount of money for expensively sold cheap booze and barely have any fun, or you will have substandard fun (on a global scale, not on the irish
) and constantly feel Damocles' sword over your head.
On top of that, during oktoberfest, the locals often go on vacation or hiatus, because they know that every gold digger in this hemisphere tries to rip of men in this few days in Munich - there are just too many drunken blokes wandering around heavily hammered after only the second Maß of beer, waiting to be bereft of the rest cash money.
Munich is expensive at best, the inner cities are recommended only for locals with experience.
You'll be much better off if you search for fun in one of the famous FKK-Clubs of Germany (the nearest ones in Augsburg or Ingolstadt), but in any case outside Munich.
You have been warned.