22years,
Both hair and nails are "DEAD", though organic. You cannot grind up nails, which are dead and inject it into your scalp and hope that your hair will grow.
Most likely, your body will recognize, your own nails as foreign material, within the epidermis of the scalp and begin to attack it and/or calcify it.
The only people who ground up nails/bones and planted it to hope that something will grow, were the Nazis, who ground up human remains to use as fertilizer for plants.