Actually, I've thought about that several times for conditioning
We can slowly increase the amount of OC and direction of the blast until we can handle full face shot. You'll still be affected but you won't have that panicked reation. Maybe Jim and I will start rolling and Burton can stand around and fire a burst around us. I've been exposed to chemical mace and the dreaded "gas chamber" several times. Let's go down to the park and work on it
My friends have stories of both pos and neg results w/ OC. As long as you have skills to back up OC you'll be better off.