1: I only use ammonia when I'm going for a max, and I only go for a max in a contest. I don't ever psyche myself up in training, as I find trianing in that state is too taxing on my recovery.
2: Start with smelling salts. Don't jump straight to nose tork. Smelling salts will wake up you, nose tork will make you run away.
Crack the capsule, bring it close to your face (like 3-6" away) and inhale slowly your first time.
3: I mean...it's probably not good for you.
For bad experiences, the first time I used nose tork, I literally threw the bottle away from me and ran from it. A buddy of mine tried it and screamed "my brain is on fire!"
4: Smelling salts, like the kind in first aid kits.
5: Ammonia is WAY more effective than any pre-workout on the market.