havent done with dye but lots of other stuff i didnt want to spray.....Take the aresol can and flip upside down and spray to remove all the propellant then you can cut the top off the can or just ram a screwdriver in and drain into a container then you can brush or wipe to your hearts content.
have fun, I've had very limited success with vinyl dye in past...works ok changing shade a bit but you are trying white to Black? can't get much harder to cover?