Materlow seems to be notoriously hard shelled.

I would suggest soaking the seeds in a glass of water until they sink. This will alow the seed shell to soften up a bit and make it easier for the taproot to push through.

I have also heard of people soaking their seeds in black tea, saying that the acidity in the tea helps to soften the shell to an even greater degree.

From this point use the standard "paper towel method" and all should be well.

Peace