Litter Training

My kitties are starting to pee in a corner of their box and they are due to start going in a litter tray right? 3ish weeks old.
So my only question is what 'litter' is safe for kittens?

I use sanicat.. I think with my rabbits litter tray as it is non clumping litter.. is that safe? But it is gritty.. hardly safe for kittens to be nibbling on?

Or will I just shred newspaper in a tray?

Thanks

There are a few organic litters that are safe even when the kits sample it. Swheat Scoop is made from wheat, Feline Pine is pine pellets, and Papurr is paper pellets.

I'v just asked my boss, who runs a pet shop and has all the possible lists of pet products, and she says those aren't sold here

Isn't it just natural for the kittens to try the litter? I mean they are curious and its something new to them....They should come to the conclusion that It doesn't taste good and spit it out....

World's Best Cat Litter is a natural litter made from corn and I highly recommend it.