Spraying the mold with bleach will kill it, but it will not remove the waste produced by the mold. That is what causes asthma attacks and allergies.
There is nothing you can put "on it" or spray it with that will remove it. It must be removed.
Mold is also very dangerous when in a confined area. It is treated the same way as asbestos. It would take a licensed mold remediator in a hazmat suit,with the area sealed in a vacuum.
It's nothing to play with.
As for those who will tell you different, ask them what license they hold and where they studied microbiology.
I hold a state mold remediator license. I'm not guessing.