I think there are so many options for a witty translation that you have to put it into context. Based on what you've written I would also suggest: "a woman's purse is (like) a black hole" (although that's more about losing things in it) or "A woman's purse is a magical mystical place, a place which defies everything physicists have taught us about space and time" or you might just go with a literal translation like "the only things you won't find in a woman's purse are xxx" (I'd probably leave out the dead soldier, it's so morbidly Hungarian :)) Hope that helps.