Take care, because pishi pishi is kind of, well... unusual. I learnt this word by singing during my Japanese class.
If an old drunk woman is bothering you, you can say something like anata wa pasa pasa desu, which means you are dry...
(konojo wa ... desu means she (is), so if you wanna say that to a girl, you should use anata wa ... desu, or you can just say pichi pichi desu, because Japanese people rarely sau the subject when it is obvious from the context).