I made a batch of marble magnets last night, only to discover that about half of them don't work. As in, they aren't magnetized and won't stick to my fridge. Does anyone know of a product that I could put on the magnet to make it work? I was thinking of magnetized paint, but do they sell that in small bottles (only about 30 need fixin') at craft stores or something? I'd rather not stick another magnet on there because that won't look as good.