I really don’t feel like testing it on myself tonight, but maybe someone out here in cyber land has already tried it and thus could offer some tips for a (theoretical) homemade self defence pepper spray substitute that a guy could give to a friend to protect herself on the way home from work.
If nothing else, I would help her find a surefire-type flashlight (instant, momentary high output) and a whistle. Blinding a would be attacker with 100+ lumens might give her those few critical seconds to get away from the situation.