Cheap static grass applicator

Hi All.   I haven’t got a workshop or spare plastic pipes laying around to do a decent job, So I went to the pound shop and purchased a cheap fly swat and a tea strainer. But my fly swat conversion job wasn’t up to the task, but today I fitted a 9 volt battery. Funny thing though the manufacturer got the wiring back to front? Nothing happened, upon investigation the battery was okay, but then I discovered that the red wire should have gone to the black wires.Best wishes Kevin