This is the first time our cats are being introduced to toilet training. You do not need to buy any expensive training products to do this. We are using a simple aluminum foil pan. Start by putting their normal litter box in the bathroom. Then put the aluminum pan in the toilet with litter in it and show them where it is. Gradually use less and less litter. Cut a small hole in one corner of the aluminum pan and gradually make the hole bigger as time goes on.
Here, Ernie is very curious and ready to jump up on the toilet. Bert is more apprehensive and takes some convincing. 
More videos to come as they learn to use it.
Duration : 0:2:25
Training your cat to sit and stay, and lie down
Miki the Wondercat pees in the human toilet.
http://www.ReallySmartGuide.com/cat — How To 
http://coolkarma.com/cat/index.html