For right now I use option one.
But I'm curious as to if there is any way to accelerate the growth of the trebeculi?
Well I have found that while Option 1 is effective, Option 2 causes much more trauma to the shin. And the whole idea of it is, that by causing trauma to the shins the body adapts and adds density to the skin on top of the shin, as well as said trauma deadening the nerves.
My theory on this subject is that induing the most trauma possible, with the most effective recovery time, is the best option. I've found Option 2, followed by 2-3 days were needed in the beginning for the Edemas to decrease in size and for the bruises to heal sufficiently enough for me to continue conditioning. The more trauma you can indue the more quickly the nerves will die and the body will adapt.
My sparring parnter, a practitioner of Northern Shaolin Kung Fu, prefers Option 3. I tested this option while still learning Shotokan Karate using a Kendo Sword and found it lacked a lot of the realistic trauma that comes from checking an actual kick.
All in all. I place them in this order of effectiveness:
1. Checking live kicks.
2. Shin kicking the lower portion of a heavy bag
3. Using a stick/Kendo Sword