Don't listen to them, they're setting you up Bro. Remember, the only part of the IM shot you feel is when you first pierce the skin. That's where the nerves are. It's going to hurt some. I'd shut my eyes and jam it in hard and fast, just don't flinch. You'll really make it hurt then.
I'm lying of course... You won't even feel it. Unless of course you use an 18ga. pin. You know, I don't think anyone has ever written about that (using an 18ga.) maybe try it and let us know how it goes. It should work well. When you think about it, injecting thick oil or suspension actually indicates using a big bore rig.