At work, she probably has a tray full of something in her hand often. If the assault (and if she is touched, that is what it is, at least where I live) occurs then, toss the load in the bg's face, followed by a good swift kick where it will hurt the most. Then go hide. If on the way home, a really really bright light (100 lumin or so) in the eyes, followed by the above mentioned kick, and then boogie.

Making your own weapon, be it a bar of soap in a sock, or tabasco in a spray bottle, only makes one look like a bad guy in the eyes of the law, and more importantly, the jury. A large ring of keys on a lanyard might be OK tho...