In order to ignite something with a spark you have to have one of two things; have a burnable material that has a very low flash point or enough easily combustable tinder to bed and smolder the spark. Vaseline won't do either of these. It takes direct flame. Maybe steel wool with a 9v battery would get it to flash over, but I've never tried it. Charcloth is great with sparks and once you get a little tinder going, then the vaseline cottonball is your easy-street to kindling going.