@TRiG That's absurd (IMO). The phrase is used a total of 6 times, the verb is not attested outside of that phrase (similarly for the cognates, per HALOT), and it was apparently was understood as simply "male". In modern English, it's not only vulgar but also quite opaque to refer to a "wall-pisser" (not sure about Wandpisser). There's nothing prissy about rendering normal Hebrew using normal English.

Interestingly, though, it's only used in these references to exterminating a household, and HALOT also mentions that it is a "contemptuous expression for masculinity." I'm not sure how such contempt could be reproduced in English, but I don't think "wall-pisser" really fits the bill.

@Susan By the way, the Gesenius’ Hebrew and Chaldee Lexicon also mentions that it is "a contemptuous designation for a little boy" (img).