Reading this brings a couple of things to mind for me.
In any certification I've had or monitored, it was always stressed to ignore the percentage ratings. Always go by the scoville heat units for power rating. I have seen sprays that were touted as being 10-15% but had ratings well below 1,000,000. Some units are sold with a big label that says "15%" with no SHU rating anywhere on the label.We were told to always go with no less than 1.5 mil
After contamination the OC can be reactivated by hot water in the shower. Causes the pores to open up and more will come in. Ask any one who has been doused, whether for training or not. If you are contaminated, take COLD showers.
I do not like that comment about the mere sight of the spray unit can defuse a situation. In the event of use by LEO it may be the case more often than with civilians as the aggressive individual is confronted with the uniformed authority figure coupled with the threat of pain compliance. Such statements can give false confidence to the fact that an individual meaning to harm you is going to back down. Many times have I seen persons act out violently due to the fact that a threat of this nature was presented. There is the possibility of posturing by the individual due to this threat being presented to them, in which case I have always allowed them to mouth off with their insults aand then leave the scene. Also there is the possibility of persons actually getting caught up "in the moment" and mouthing off back at a threat and feeling that extra courage because they have an ace up their sleeve with the OC in hand. Not everyone can control themselves in such situations and could act before thinking. IMHO it is always best to keep such tools concealed or out of sight until used so as to prevent escalation of a situation and to add the element of surprise in one's defence.
Just my $0.02 worth.