also, can you dilute the bleach, like say, 2 parts javex to ten parts water?
You can´t remove it using bleach , you will be wasting your time with bleach . Although it seems to work , it as only a temporary effect. The mold will recur in a matter of months. Use a proprietary fungicide, depending on how severe, you might need a number of applications. Try and keep your basement well ventilated, or use a dehumidifier every now and then