Yes, I agree, nerves are there for a reason. Conditioning parts of your body is not the same as deadening nerves. I have done and continue to do pretty heavy body conditioning. When I started competing in full contact events I did alot more than I do now. There have been some great posts and some not so great ones here. First, you need to seek instruction. Second, you do not want to injure yourself in any way. If your being offered instruction in conditioning by injury, run away. You dont want to damage nerves, break shins, or anything like that. You must start slow. If you get injured (even a deep bruise) your body must heal before continuing the conditioning. Therefore you want to condition and increase only enough to not injure yourself. That means slowly. Using a bottle is good; we use staffs or large dowels, roll then tapping on the shin. We condition shins, calves, in/out thigh, ribs, stomach, arms, hands, shoulders, kidneys and back. This is not done by injury; I keep repeating that because there are so many misconceptions out there about body conditioning. I seen great success in my training but have put in the time. Usually any quick fix is not worth the risks.
However, we view conditioning a bit different. I'm not conditioning my body so I can meet a shin kick with a shin kick of my own and beat it. I use body conditioning as an insuarnce policy if you will. If you do hit me I am conditioned. Also, when I hit you, even if not full power, it will hurt you more.
Just my few cents,
7sm