I know it's been a while since anyone posted in this thread but I was also intrigued by the use of 'nation sack'. I'd always assumed it was slang for a wallet or purse - something to carry money in. But I looked it up and found the same 'lucky mojo' page which reynard quotes above - and it's clear that the real meaning of the word is nothing to do with money per se - it's a bag of voodoo charms which a woman uses in order to keep her man true. Since she keeps it hidden from everyone by hiding it in her skirts - where nobody will look - if it's code for anything it's code for what in English folk songs is referred to as the 'cuckoo's nest'. So I think Dirk is simply using it slightly incorrectly here. This is not a criticism at all - it's a great song and the words sound great - they just don't mean quite what he thought they meant.