Acid is completely different to PCP. PCP affects pain receptors, effectively it can neutralize shock responses that would normally prevent you from doing things, such as moving while you have a bullet in your stomach. To somebody not on PCP, getting shot would be a WORLD of pain, and would instantly floor you, if hit anywhere in the torso. With PCP, you wouldn't really feel it. It's completely different to Acid, which merely stimulates parts of your brain to give good feelings and visual imagery.
PCP can affect muscle responses with tasers, it affects your body quite a lot more than you seem to think. It's pretty damn realistic. Here's a story about one such incident where drugs can affect taser effectiveness: http://www.nydailynews.com/news/crim...icle-1.2351706