Does the persistence of the trace of prostatic fluid (madhy) after washing affect the purity of the garment, and does it contaminate other clothes when washed with it in the washing machine?

Usually, the purification of madhy (pre-seminal fluid) and similar impurities is achieved by customary washing. If a trace of it remains, it must be removed until the impurity is certainly gone. If all clothes are washed until it is highly probable that the impurity has been removed, then all of them are purified.