Thirteen star, O.C sprays work very good, period. I have used the stuff extensively in my LEO career. I have been sprayed a few times, a few times deliberate ( we need to get sprayed before we can carry the can, and "cop fun"), and have been hit a few times during apprehension a suspect. there is always some contamination with OC, foam the least, then stream, then fog.
If u never been thru the ordeal u think u are going to die when they spray it in your face. But u get "used" to it after a while, the floating particles just form a nuissance. If u know the effects of the spray u know what is happening, so they aren't so frightening.
O.C. has very strong psychological benefits, when hit direct in the face, your eyes close automatically, they start to burn extremely painfull, your nose and mouth start to run, u can start to vomit and your airway gets restricted untill u can just breath enough just to stay alive. All these factors combined transmits a gaint "shock" to the nervous system of the target. His brain receives massive pain indicators and he panics and wants to get away from the spray.
If u spray yourself a lot u will feel the same pain, but your brain will know, "hey i am not going to die, this stops after a few minutes and within 30' everything is over. Stay calm, keep breathing and relax". i know my collegues who spray at each other as "fun" or spray on their sandwich and stuff!
Just get a good can (FOX) and go to your backyard. Spray with it , stand still and u will feel the effect in a low level by air contamination. then u can spray and run thru the cloud. If you are really tough ask a friend to give u a short blast in the face.
When u know what the spray does u will know what the BG will feel when he unexpected gets hit by the liquid in his face. Don't threathen with the spray, keep it hidden untill he is close and he forms a real threath, and then spray the whole can in his face! don't stop spraying u will nedd to get a new can anyway so why waste good O.C.
When he is down go to te police station, or run like hell.