Maybe you could use WAŃKA WSTAŃKA (van-ka ftstan-ka) for your cock, but not sure. WAŃKA is a russian name.
For womens thang you can use KASIA. Like: "Pokaż Kasię!"
Or you can use the word SOWA (sova = owl), you can say CHYBA CI SOWA ZDECH£A, indicating not-so-good smell.
Related: Baśka and Wacek?
Anyone know how, when and why certain parts of the body got people names such as Baśka or Wacek?
I dunno...I heard only about ptaszek i gniazdko.. :) I must say I have never heard the name Baśka to be used that way.
The question "when" might be hard to answer.
For "why" these might be the answers:
1) people wanted to avoid using other (let's call them "real") names for some reason?
2) because some people found it funny to call things with these names?