I am not sure how this is relevant to women being attacked by men? Do many rapists train BJJ to purple belt in order to be able to rape women who may be trained to fight on the ground?At her best she still got tapped by male purple belts, and she was the world's highest level black belt at one point in time.
Not everyone lives in a country where the carrying of concealed weapons is legal. It is therefore not "practical" advice, instead it is illegal, dangerous,and highly irresponsible advice. By all means present it as your "opinion", which is what it is, but please don't present it is "practical".If you want practical advice ......then get a concealable weapon and learn how to use it.