If the seeds wernt mature, they wouldnt germinate, normally. They need to be a dark brown. It can take up to 2 weeks [but that is a hell of along time] to germinate. Also, NEVER even think of using any ferts untill at least 3 weeks into the grow.

Dont touch the white tap root.

And use soil, it's natural. I've never heard of using cat litter for growing.

And make sure the soil is aireated, and has good drainage.