Re: OC spray - Here's a different view from trainer George Matheis, aka Mercop, on his blog at moderncombativesystems.net (snipped for length here):
More on the problems with OC spray
Selection-any of them is nasty.
Carry-need to be in your hand and nobody carries it in their hand.
Deployment- Still looking for citizens stories of how they used it during an attack, just with someone standing at conversation distance, although all stories are appreciated.
In my opinion the idea of using OC to defend yourself during a violent spontaneous attack is basically an urban legend.
Do yourself a favor, get them a sturdy pen, and train them. Teach them to stab into the back of a hand that grabs them, and into the face and neck of the attacker. Pizza boxes are great for this since the get the sensation of puncturing something.
Face / Neck / Head / Hands hit with impact weapon until you can get away
Stopping wasting you money on feelgood bullshit and fairy dust.- George"