Nah, that's about a 7. I did it playing football, and it's sore as f**k, but....
I dislocated my shoulder (the full, ball-out-the-socket dislocation too) playing rugby when the entire pack landed on me, swinging my left arm right around and pinning it across my shoulder blades. I was lying facing right, and could see both my right and left hands, almost together close to my face, but with my left coming round to the right around my back. My collar bone dislocated at the same time.
That was about a 9. Subsequent dislocations (three of them) have been about an 8. One of them I was two miles from home in the middle of nowhere and I passed out trying to get back. Eventually got there, and I have to say my dog, who looked like Lassie after all, was absolutely no fucking help whatsoever.
The worst pain I have ever felt was dislocating my knee cap, during which my femur pushed into my knee joint and snapped my meniscus, which then ended up in the back of my knee joint, meaning I couldn't straighten my leg properly for nine months until they eventually took it out. I knew I was in trouble when the laughing gas in the ambulance didn't seem to be doing anything. It got worse when I realised the morphine at the hospital wasn't really taking the edge off either.
I'd give that one a ten.
Standing on a plug IS disproportionately painful, but still no more than a 6.
I don't have any tattoos.