Homemade hair bleach can be made using a hydrogen peroxide and mild bleach mixture, according to HealthGuidance.org. It is important that both are suitable for hair use, as some chemicals may damage hair or cause skin injury and irritation.
HealthGuidance.org goes on to give more complete details on bleaching hair at home. It recommends sectioning off areas that do not need to be lightened with aluminum foil, then painting the exposed areas with a dye brush or another applicator. The mixture should be left on the hair for 30 to 35 minutes, depending on the desired color. These steps may be repeated if the color goal is not reached.