I've done it a couple of times as a layover. There's an FKK or two on the same outskirts as the airport and especially in this weather I'd head there, even just to get similar facilities you'd find in an airport VIP lounge but with naked women and available shags thrown in.
If you want the other types of encounter (Eros Centres, i.e. the short-time walk ups, or for instance there's a 'tantric' place downtown) just jump on the train to central station and it's walking distance. tbh I've not been impressed with the quality of these recently, even compared to other cities' Eros Centres. If you have to try just for the experience, there's one or two I think a short taxi ride from the main FKKs.
There again, don't rely on the specifics of this too much. I tend to get several German cities mixed up as they seem to look the same to me with a few exceptions. Jerboa will keep you right.
