I have little positive experience in germinating these mammillary.
I want to add at least some useful idea.
It can be sent in the future someone on the right path.
1. Somehow I sowed Sanchez-mejorada. The seeds were fresh and germination 40 %.
2. The doctors have the tool, scarifier. I think it is useful to You. And microscop.
Carefully open the sterile and soaked seed. You need to ensure that the fetus is a life.
The seeds can simply be an empty shell.
3. The sterilization may be performed acid, a strong solution of potassium permanganate, and bleach. These
medications little eat the shell of the seed. A long and thorough rinsing after burn seeds.
4. All these manipulations are made after the first soaking and germination failed.
Mechanical soaking alternating water air. Dripping water, melting snow or ice.
From the word IV.